From JHARKNESS373 at COMCAST.NET Tue Oct 2 16:01:06 2007 From: JHARKNESS373 at COMCAST.NET (JOHN HARKNESS) Date: Tue, 2 Oct 2007 17:01:06 -0400 Subject: [wxqc] Do I have an Issue? Message-ID: <000a01c80537$5a51ce70$6401a8c0@Home> I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don't want to make changes if I don't need to, but would like to stay accurate. My CWOP readings have also gone awry. I don't know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/8177e59c/attachment.html From philip at gladstonefamily.net Tue Oct 2 16:12:54 2007 From: philip at gladstonefamily.net (Philip Gladstone) Date: Tue, 02 Oct 2007 17:12:54 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <000a01c80537$5a51ce70$6401a8c0@Home> References: <000a01c80537$5a51ce70$6401a8c0@Home> Message-ID: <4702B456.4030003@gladstonefamily.net> JOHN HARKNESS wrote: > > I have had my weather station (Davis ProVantage2) for nearly a year > now, and have had no problems. Over the past couple of weeks, I have > noticed a drop in my quality control graphs during the nightime hours > in temp and then it is greater during the day. I thought I had siting > problems with the station, so I reverted back to the recommended > siting guidelines from Davis. There was no change in trend. My reading > are very close to the nearby stations in FindU > but are > horrendously different from the readings I was close to from nearby > stations on weatherunderground.. I don?t want to make changes if I > don?t need to, but would like to stay accurate. My CWOP > readings have also > gone awry. I don?t know if that is because of new stations or not. Any > help would be greatly appreciated. > > John > > john at horshamweather.com > John From a quick look, I would say that what has happened is that a new station has come online in your area which is providing poor quality data into MADIS, and this is upsetting the analysis. The can see this when the 'analysis' line has sharp spikes in it as this station drops in and out of the analysis. You *may* be able to find this station by clicking on the 'Madis data display' link near the bottom of the page -- this shows you in the middle and the offending station is one of the surrounding stations...... It may not be a CWOP station. Philip From N3UJJ at N3UJJ.COM Tue Oct 2 16:23:19 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 17:23:19 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <000a01c80537$5a51ce70$6401a8c0@Home> References: <000a01c80537$5a51ce70$6401a8c0@Home> Message-ID: <001f01c8053a$758ebd30$60ac3790$@COM> John, I also have noticed the same thing. Funny thing is I have another CWOP station within 2 blocks of my station that seems to echo some (but not all) the same readings I get. I noticed that your station as well as mine are located on masts high up above the roof of our homes (great to have pictures). One thing is common is that ALL 3 of our stations are Davis Vantage Pros. Scott Gillis (N3UJJ) My Current Location My Weather Station From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of JOHN HARKNESS Sent: Tuesday, October 02, 2007 5:01 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Do I have an Issue? I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don't want to make changes if I don't need to, but would like to stay accurate. My CWOP readings have also gone awry. I don't know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/76bd716c/attachment-0001.html From N3UJJ at N3UJJ.COM Tue Oct 2 16:54:24 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 17:54:24 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <000a01c80537$5a51ce70$6401a8c0@Home> References: <000a01c80537$5a51ce70$6401a8c0@Home> Message-ID: <003d01c8053e$cccd58a0$666809e0$@COM> John, I noticed that my errors started on 9/12/07, prior to that all of my reports were clean Any chance you see the same thing? Scott Gillis (N3UJJ) From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of JOHN HARKNESS Sent: Tuesday, October 02, 2007 5:01 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Do I have an Issue? I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don't want to make changes if I don't need to, but would like to stay accurate. My CWOP readings have also gone awry. I don't know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/8857a0c8/attachment.html From alaparos at taconic.net Tue Oct 2 16:48:27 2007 From: alaparos at taconic.net (Gary Ferdinand) Date: Tue, 02 Oct 2007 17:48:27 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <000a01c80537$5a51ce70$6401a8c0@Home> References: <000a01c80537$5a51ce70$6401a8c0@Home> Message-ID: <4702BCAB.804@taconic.net> John, Just a thought but how strong is your battery? Perhaps it no longer is capable of supplying sufficient power at night. During the day the solar cells do the trick. Try a strip chart on the ISS signal and see if there's anything to be learned. Good luck Gary JOHN HARKNESS wrote: > > I have had my weather station (Davis ProVantage2) for nearly a year > now, and have had no problems. Over the past couple of weeks, I have > noticed a drop in my quality control graphs during the nightime hours > in temp and then it is greater during the day. I thought I had siting > problems with the station, so I reverted back to the recommended > siting guidelines from Davis. There was no change in trend. My reading > are very close to the nearby stations in FindU > but are > horrendously different from the readings I was close to from nearby > stations on weatherunderground.. I don?t want to make changes if I > don?t need to, but would like to stay accurate. My CWOP > readings have also > gone awry. I don?t know if that is because of new stations or not. Any > help would be greatly appreciated. > > John > > john at horshamweather.com > > www.horshamweather.com > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From N3UJJ at N3UJJ.COM Tue Oct 2 18:06:13 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 19:06:13 -0400 Subject: [wxqc] Errors on Davis Wireless Units ????? In-Reply-To: <000a01c80537$5a51ce70$6401a8c0@Home> References: <000a01c80537$5a51ce70$6401a8c0@Home> Message-ID: <00c901c80548$d55a53b0$800efb10$@COM> I Just noticed something VERY Interesting. It's easy to think that the problem is somewhere else (who wants to think that the problem is on their station), after John & I started taking about how we were having the same problem, and I pointed out that I had almost perfect Quality checks until Sept 21st . Then a light bulb went off, didn't I notice my wireless reception graphs were a little funny the last time I looked at them. I remember asking myself why would my graphs drop when the fall hit. Check this link out (it my wireless reception graph) http://weather.n3ujj.com/week/ReceptionHistory.gif Looks like my errors started when my reception dropped off, while I'm not saying this is the answer (until I run a few more tests), but it sure looks like a wireless reception problem COULD lead to errors. Has anyone else had this problem? Scott Gillis (N3UJJ) My Current Location My Weather Station From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of JOHN HARKNESS Sent: Tuesday, October 02, 2007 5:01 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Do I have an Issue? I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don't want to make changes if I don't need to, but would like to stay accurate. My CWOP readings have also gone awry. I don't know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/263ff988/attachment.html From N3UJJ at N3UJJ.COM Tue Oct 2 18:22:16 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 19:22:16 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <4702BCAB.804@taconic.net> References: <000a01c80537$5a51ce70$6401a8c0@Home> <4702BCAB.804@taconic.net> Message-ID: Gary, Looks like you are right... Here is an hourly graph on my reception: http://weather.n3ujj.com/hour/ReceptionHistory.gif you can see it drop at night, and it only seems to have started since the weather has cooled. This unit is 3 months old, who would think it should have a battery problem so soon. Let's see what Davis is going to have to say about this (smile) Scott Gillis (N3UJJ) My Current Location My Weather Station -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gary Ferdinand Sent: Tuesday, October 02, 2007 5:48 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Do I have an Issue? John, Just a thought but how strong is your battery? Perhaps it no longer is capable of supplying sufficient power at night. During the day the solar cells do the trick. Try a strip chart on the ISS signal and see if there's anything to be learned. Good luck Gary JOHN HARKNESS wrote: > > I have had my weather station (Davis ProVantage2) for nearly a year > now, and have had no problems. Over the past couple of weeks, I have > noticed a drop in my quality control graphs during the nightime hours > in temp and then it is greater during the day. I thought I had siting > problems with the station, so I reverted back to the recommended > siting guidelines from Davis. There was no change in trend. My reading > are very close to the nearby stations in FindU > but are > horrendously different from the readings I was close to from nearby > stations on weatherunderground.. I don't want to make changes if I > don't need to, but would like to stay accurate. My CWOP > readings have also > gone awry. I don't know if that is because of new stations or not. Any > help would be greatly appreciated. > > John > > john at horshamweather.com > > www.horshamweather.com > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/2011ee80/attachment-0001.html From JHARKNESS373 at COMCAST.NET Tue Oct 2 18:31:01 2007 From: JHARKNESS373 at COMCAST.NET (JOHN HARKNESS) Date: Tue, 2 Oct 2007 19:31:01 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: Message-ID: <000001c8054c$4baa1430$6401a8c0@Home> I wish I could say that it was the problem....the only issue is that I have a Cabled Davis 6152C (ProVantage2 Cabled)... I hope this DOES solve your issue, and im glad I brought it up!! Maybe my issue is because of other Wireless stations in the area!! John john at horshamweather.com www.horshamweather.com From slottech at gbis.com Tue Oct 2 20:11:35 2007 From: slottech at gbis.com (Richard) Date: Tue, 2 Oct 2007 18:11:35 -0700 Subject: [wxqc] Errors on Davis Wireless Units ????? In-Reply-To: <00c901c80548$d55a53b0$800efb10$@COM> References: <000a01c80537$5a51ce70$6401a8c0@Home> <00c901c80548$d55a53b0$800efb10$@COM> Message-ID: <04de01c8055a$5805cdb0$0501a8c0@Richardn> Hmm... you're a Ham too. I had a similar problem with reception, although it didn't affect my data quality (it didn't seem to, anyway), but it did cause a low battery warning on the ISS in the evenings. I spent quite a few days with Davis tech support (great guys, their tech support is tops!), as I had to call from work, they'd tell me something to try, and I go home, try it and call them the next day with the results. After much troubleshooting, it turned out to be the radios I use when I'm at home. In the evenings and most of the weekend, I have two 2m radios and one 440 radio in scan mode listening for traffic on the local repeaters, and the console was located on the wall, a couple of feet away from the radios. The tech suggested I relocate the console, and I did, mounting it on the wall behind me. The problem immediately disappeared and hasn't returned. Thinking about it later, it could have also been my computer causing the interference. Richard www.n7tgb.net _____ From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of N3UJJ Sent: Tuesday, October 02, 2007 4:06 PM To: 'Discussion of weather data quality issues' Subject: [wxqc] Errors on Davis Wireless Units ????? I Just noticed something VERY Interesting. It's easy to think that the problem is somewhere else (who wants to think that the problem is on their station), after John & I started taking about how we were having the same problem, and I pointed out that I had almost perfect Quality checks until Sept 21st . Then a light bulb went off, didn't I notice my wireless reception graphs were a little funny the last time I looked at them. I remember asking myself why would my graphs drop when the fall hit. Check this link out (it my wireless reception graph) http://weather.n3ujj.com/week/ReceptionHistory.gif Looks like my errors started when my reception dropped off, while I'm not saying this is the answer (until I run a few more tests), but it sure looks like a wireless reception problem COULD lead to errors. Has anyone else had this problem? Scott Gillis (N3UJJ) My Current Location My Weather Station From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of JOHN HARKNESS Sent: Tuesday, October 02, 2007 5:01 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Do I have an Issue? I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don't want to make changes if I don't need to, but would like to stay accurate. My CWOP readings have also gone awry. I don't know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/59e2136b/attachment.html From slottech at gbis.com Tue Oct 2 20:17:15 2007 From: slottech at gbis.com (Richard) Date: Tue, 2 Oct 2007 18:17:15 -0700 Subject: [wxqc] Do I have an Issue? In-Reply-To: References: <000a01c80537$5a51ce70$6401a8c0@Home> <4702BCAB.804@taconic.net> Message-ID: <04e301c8055b$2263ae60$0501a8c0@Richardn> I found out from the Davis techs that the ISS doesn't use the battery at night, it actually uses a capacitor, charged during daylight, to supply power at night. It takes many hours to discharge it during normal use; I know because I replaced a transmitter board on mine and the old one was still happily transmitting well over twelve hours later. Only when the Cap is discharged, does it use the backup battery. Richard www.n7tgb.net _____ From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of N3UJJ Sent: Tuesday, October 02, 2007 4:22 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Do I have an Issue? Gary, Looks like you are right... Here is an hourly graph on my reception: http://weather.n3ujj.com/hour/ReceptionHistory.gif you can see it drop at night, and it only seems to have started since the weather has cooled. This unit is 3 months old, who would think it should have a battery problem so soon. Let's see what Davis is going to have to say about this (smile) Scott Gillis (N3UJJ) My Current Location My Weather Station -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gary Ferdinand Sent: Tuesday, October 02, 2007 5:48 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Do I have an Issue? John, Just a thought but how strong is your battery? Perhaps it no longer is capable of supplying sufficient power at night. During the day the solar cells do the trick. Try a strip chart on the ISS signal and see if there's anything to be learned. Good luck Gary JOHN HARKNESS wrote: > > I have had my weather station (Davis ProVantage2) for nearly a year > now, and have had no problems. Over the past couple of weeks, I have > noticed a drop in my quality control graphs during the nightime hours > in temp and then it is greater during the day. I thought I had siting > problems with the station, so I reverted back to the recommended > siting guidelines from Davis. There was no change in trend. My reading > are very close to the nearby stations in FindU > but are > horrendously different from the readings I was close to from nearby > stations on weatherunderground.. I don't want to make changes if I > don't need to, but would like to stay accurate. My CWOP > readings have also > gone awry. I don't know if that is because of new stations or not. Any > help would be greatly appreciated. > > John > > john at horshamweather.com > > www.horshamweather.com > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/d74b27c4/attachment-0001.html From JHARKNESS373 at COMCAST.NET Tue Oct 2 20:42:35 2007 From: JHARKNESS373 at COMCAST.NET (JOHN HARKNESS) Date: Tue, 2 Oct 2007 21:42:35 -0400 Subject: [wxqc] Do I have an issue? In-Reply-To: Message-ID: <000001c8055e$acc7d060$6401a8c0@Home> Gary, I have a cabled version of the VantagePro2....its not an issue of reception. Re-siting my station did nothing to help or hinder my recent readings. I thought i was getting dead air .... but that was not the problem. People who frequent my web page are asking me why my readings are lower than others, so I checked with 3 different thermometers and they are all within .2 degrees of my posted readings. However, when I check my FindU local stations, they are higher at night and my temp seems to be about 5-7 degrees lower than the nearest reporting station (Willow Grove Naval Air Station) which is about a mile from me. Im just pulling my hair out trying to find out why, all of a sudden, i don't even come close to other stations at night. Maybe im just being over analytical of the situation, but accuracy is very important to me. john at horshamweather.com www.horshamweather.com From N3UJJ at N3UJJ.COM Tue Oct 2 21:27:20 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 22:27:20 -0400 Subject: [wxqc] Errors on Davis Wireless Units ????? In-Reply-To: <04de01c8055a$5805cdb0$0501a8c0@Richardn> References: <000a01c80537$5a51ce70$6401a8c0@Home> <00c901c80548$d55a53b0$800efb10$@COM> <04de01c8055a$5805cdb0$0501a8c0@Richardn> Message-ID: Hmmm . One more possibility, I started moving my office about the time I installed my Davis, and the HamShack stayed in the original office. I started moving the HamShack to the new office last month, and that?s about the time I moved the Rig control computer (click link for picture) that controls the radios, I didn?t even give that a thought because I have been on the air the whole time (HF, VHF & UHF) (up to 500 watts on HF, and 65 watts on VHF/UHF). At no time did any Ham activity seem to cause a problem with the Davis, BUT I didn?t consider the computer (which has a lot of cables running to the radios) . Well that will be an easy test, I?ll power down the Rig control computer for a few days.. As I?m typing this I just got a weather quality report: Date UTC Alt (mb) Temp ?F DewPt ?F Wind Dir Speed knts 02-OCT-2007 Errs 0/96 8/96 0/96 0/96 0/96 02-OCT-2007 Smry +0.7 0.22 -3 1.90 -1 1.28 +65 46 +1.8 0.8 Almost no errors (and the rig control computer is on). Well . Like Philip says, figuring out the problems are half the fun (and look what we will learn) Anyway, the Rig Control Computer gets turned off in 10 minutes (sigh, no PSK31 for a week) From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Richard Sent: Tuesday, October 02, 2007 9:12 PM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Errors on Davis Wireless Units ????? Hmm... you're a Ham too. I had a similar problem with reception, although it didn't affect my data quality (it didn't seem to, anyway), but it did cause a low battery warning on the ISS in the evenings. I spent quite a few days with Davis tech support (great guys, their tech support is tops!), as I had to call from work, they'd tell me something to try, and I go home, try it and call them the next day with the results. After much troubleshooting, it turned out to be the radios I use when I'm at home. In the evenings and most of the weekend, I have two 2m radios and one 440 radio in scan mode listening for traffic on the local repeaters, and the console was located on the wall, a couple of feet away from the radios. The tech suggested I relocate the console, and I did, mounting it on the wall behind me. The problem immediately disappeared and hasn't returned. Thinking about it later, it could have also been my computer causing the interference. Richard www.n7tgb.net _____ From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of N3UJJ Sent: Tuesday, October 02, 2007 4:06 PM To: 'Discussion of weather data quality issues' Subject: [wxqc] Errors on Davis Wireless Units ????? I Just noticed something VERY Interesting. It?s easy to think that the problem is somewhere else (who wants to think that the problem is on their station), after John & I started taking about how we were having the same problem, and I pointed out that I had almost perfect Quality checks until Sept 21st . Then a light bulb went off, didn?t I notice my wireless reception graphs were a little funny the last time I looked at them. I remember asking myself why would my graphs drop when the fall hit. Check this link out (it my wireless reception graph) http://weather.n3ujj.com/week/ReceptionHistory.gif Looks like my errors started when my reception dropped off, while I?m not saying this is the answer (until I run a few more tests), but it sure looks like a wireless reception problem COULD lead to errors. Has anyone else had this problem? Scott Gillis (N3UJJ) My Current Location My Weather Station From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of JOHN HARKNESS Sent: Tuesday, October 02, 2007 5:01 PM To: wxqc at lists.gladstonefamily.net Subject: [wxqc] Do I have an Issue? I have had my weather station (Davis ProVantage2) for nearly a year now, and have had no problems. Over the past couple of weeks, I have noticed a drop in my quality control graphs during the nightime hours in temp and then it is greater during the day. I thought I had siting problems with the station, so I reverted back to the recommended siting guidelines from Davis. There was no change in trend. My reading are very close to the nearby stations in FindU but are horrendously different from the readings I was close to from nearby stations on weatherunderground.. I don?t want to make changes if I don?t need to, but would like to stay accurate. My CWOP readings have also gone awry. I don?t know if that is because of new stations or not. Any help would be greatly appreciated. John john at horshamweather.com www.horshamweather.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071002/0219961d/attachment.html From alaparos at taconic.net Tue Oct 2 21:28:28 2007 From: alaparos at taconic.net (Gary Ferdinand) Date: Tue, 02 Oct 2007 22:28:28 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <04e301c8055b$2263ae60$0501a8c0@Richardn> References: <000a01c80537$5a51ce70$6401a8c0@Home> <4702BCAB.804@taconic.net> <04e301c8055b$2263ae60$0501a8c0@Richardn> Message-ID: <4702FE4C.7090200@taconic.net> OK, Richard. It was a wild idea to start with :-) I'm sure Davis knows best. My logic was that we have (here in NY) much less daylight hours and those that exist have less solarization. Wx is more cloudy now further reducing solarization. So it's not a stretch to me to speculate that over a period when lower solar panel output existed, the cap might need recharging from the battery. But, it's also colder now, and at night, and that can greatly reduce available battery voltage. I had some similar problems a couple weeks ago, replaced the battery, and all is well. YMMV. Good luck and 73, Gary W2CS ;-) Richard wrote: > I found out from the Davis techs that the ISS doesn't use the battery > at night, it actually uses a capacitor, charged during daylight, to > supply power at night. It takes many hours to discharge it during > normal use; I know because I replaced a transmitter board on mine and > the old one was still happily transmitting well over twelve hours > later. Only when the Cap is discharged, does it use the backup battery. > *Richard* > *www.n7tgb.net* > > ------------------------------------------------------------------------ > *From:* wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] *On Behalf Of *N3UJJ > *Sent:* Tuesday, October 02, 2007 4:22 PM > *To:* 'Discussion of weather data quality issues' > *Subject:* Re: [wxqc] Do I have an Issue? > > Gary, > > Looks like you are right... > > Here is an hourly graph on my reception: > http://weather.n3ujj.com/hour/ReceptionHistory.gif you can see it drop > at night, and it only seems to have started since the weather has cooled. > > This unit is 3 months old, who would think it should have a battery > problem so soon. > > Let?s see what Davis is going to have to say about this (smile) > > *Scott Gillis (N3UJJ)* > > /My Current Location / > > /My Weather Station / > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gary > Ferdinand > Sent: Tuesday, October 02, 2007 5:48 PM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Do I have an Issue? > > John, > > Just a thought but how strong is your battery? Perhaps it no longer is > > capable of supplying sufficient power at night. During the day the solar > > cells do the trick. Try a strip chart on the ISS signal and see if > > there's anything to be learned. Good luck > > Gary > > JOHN HARKNESS wrote: > > > > > > I have had my weather station (Davis ProVantage2) for nearly a year > > > now, and have had no problems. Over the past couple of weeks, I have > > > noticed a drop in my quality control graphs during the nightime hours > > > in temp and then it is greater during the day. I thought I had siting > > > problems with the station, so I reverted back to the recommended > > > siting guidelines from Davis. There was no change in trend. My reading > > > are very close to the nearby stations in FindU > > > but are > > > horrendously different from the readings I was close to from nearby > > > stations on weatherunderground.. I don?t want to make changes if I > > > don?t need to, but would like to stay accurate. My CWOP > > > readings have also > > > gone awry. I don?t know if that is because of new stations or not. Any > > > help would be greatly appreciated. > > > > > > John > > > > > > john at horshamweather.com > > > > > > www.horshamweather.com > > > > > > ------------------------------------------------------------------------ > > > > > > _______________________________________________ > > > wxqc mailing list > > > Post messages to wxqc at lists.gladstonefamily.net > > > To unsubcribe or change delivery options, please go to: > > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > > > The contents of this message are the responsibility of the author. > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > ------------------------------------------------------------------------ > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From alaparos at taconic.net Tue Oct 2 21:33:49 2007 From: alaparos at taconic.net (Gary Ferdinand) Date: Tue, 02 Oct 2007 22:33:49 -0400 Subject: [wxqc] Do I have an issue? In-Reply-To: <000001c8055e$acc7d060$6401a8c0@Home> References: <000001c8055e$acc7d060$6401a8c0@Home> Message-ID: <4702FF8D.4090600@taconic.net> John, give some thought to topography. If you're at the bottom of a valley or even nestled in among some hills, as we get into the cooler season, the cool air up top of the hills will fall into your location, depressing the temperature. I live in such a situation and frequently see overnight temperatures several degrees lower than surrounding stations. Since you've crossed checked your temperature readings with other instruments, I'd start asking what is it about your location that might be causing the (true) lower temperatures. Gary JOHN HARKNESS wrote: > Gary, > > I have a cabled version of the VantagePro2....its not an issue of reception. > Re-siting my station did nothing to help or hinder my recent readings. I > thought i was getting dead air .... but that was not the problem. People > who frequent my web page are asking me why my readings are lower than > others, so I checked with 3 different thermometers and they are all within > .2 degrees of my posted readings. However, when I check my FindU local > stations, they are higher at night and my temp seems to be about 5-7 degrees > lower than the nearest reporting station (Willow Grove Naval Air Station) > which is about a mile from me. Im just pulling my hair out trying to find > out why, all of a sudden, i don't even come close to other stations at > night. Maybe im just being over analytical of the situation, but accuracy > is very important to me. > > john at horshamweather.com > > www.horshamweather.com > > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > From gerry.creager at tamu.edu Tue Oct 2 21:36:53 2007 From: gerry.creager at tamu.edu (Gerry Creager) Date: Tue, 02 Oct 2007 21:36:53 -0500 Subject: [wxqc] Do I have an issue? In-Reply-To: <000001c8055e$acc7d060$6401a8c0@Home> References: <000001c8055e$acc7d060$6401a8c0@Home> Message-ID: <47030045.5060409@tamu.edu> It's not unreasonable to consider that you are in a microclimate that's different than, say, Willow Grove. If you're seeing a consistent tendency and getting good MADIS checks, you *might* have a problem, or you just might not have similar readings to your neighbors. gerry JOHN HARKNESS wrote: > Gary, > > I have a cabled version of the VantagePro2....its not an issue of reception. > Re-siting my station did nothing to help or hinder my recent readings. I > thought i was getting dead air .... but that was not the problem. People > who frequent my web page are asking me why my readings are lower than > others, so I checked with 3 different thermometers and they are all within > .2 degrees of my posted readings. However, when I check my FindU local > stations, they are higher at night and my temp seems to be about 5-7 degrees > lower than the nearest reporting station (Willow Grove Naval Air Station) > which is about a mile from me. Im just pulling my hair out trying to find > out why, all of a sudden, i don't even come close to other stations at > night. Maybe im just being over analytical of the situation, but accuracy > is very important to me. > > john at horshamweather.com > > www.horshamweather.com > > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 From N3UJJ at N3UJJ.COM Tue Oct 2 22:13:11 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Tue, 2 Oct 2007 23:13:11 -0400 Subject: [wxqc] Do I have an issue? In-Reply-To: <47030045.5060409@tamu.edu> References: <000001c8055e$acc7d060$6401a8c0@Home> <47030045.5060409@tamu.edu> Message-ID: One thing that was confusing the issue for my problem was the fact that I have a CWOP Station that is literally 2 blocks away from my location (but seems to offline every other week)(most likely has USB cable). The following links are examples where MADIS disagreed both our stations: http://weather.gladstonefamily.net/qchart/AS693?date=20070905&addnl=C6040 http://weather.gladstonefamily.net/qchart/AS693?date=20070906&addnl=C6040 http://weather.gladstonefamily.net/qchart/AS693?date=20070907&addnl=C6040 http://weather.gladstonefamily.net/qchart/AS693?date=20070909&addnl=C6040 http://weather.gladstonefamily.net/qchart/AS693?date=20070910&addnl=C6040 But I think this is a great discussion, that has brought up some GREAT points. -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gerry Creager Sent: Tuesday, October 02, 2007 10:37 PM To: Discussion of weather data quality issues Subject: Re: [wxqc] Do I have an issue? It's not unreasonable to consider that you are in a microclimate that's different than, say, Willow Grove. If you're seeing a consistent tendency and getting good MADIS checks, you *might* have a problem, or you just might not have similar readings to your neighbors. gerry JOHN HARKNESS wrote: > Gary, > > I have a cabled version of the VantagePro2....its not an issue of reception. > Re-siting my station did nothing to help or hinder my recent readings. I > thought i was getting dead air .... but that was not the problem. People > who frequent my web page are asking me why my readings are lower than > others, so I checked with 3 different thermometers and they are all within > .2 degrees of my posted readings. However, when I check my FindU local > stations, they are higher at night and my temp seems to be about 5-7 degrees > lower than the nearest reporting station (Willow Grove Naval Air Station) > which is about a mile from me. Im just pulling my hair out trying to find > out why, all of a sudden, i don't even come close to other stations at > night. Maybe im just being over analytical of the situation, but accuracy > is very important to me. > > john at horshamweather.com > > www.horshamweather.com > > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -- Gerry Creager -- gerry.creager at tamu.edu Texas Mesonet -- AATLT, Texas A&M University Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From dshelms at comcast.net Tue Oct 2 22:51:42 2007 From: dshelms at comcast.net (Dave Helms) Date: Tue, 02 Oct 2007 23:51:42 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <4702FE4C.7090200@taconic.net> References: <000a01c80537$5a51ce70$6401a8c0@Home> <4702BCAB.804@taconic.net> <04e301c8055b$2263ae60$0501a8c0@Richardn> <4702FE4C.7090200@taconic.net> Message-ID: <470311CE.2040409@comcast.net> Hey Guys, John's weather reports (CW6611) are excellent. As Philip said, the problems are with a neighboring station: http://weather.gladstonefamily.net/qchart/C6611?date=20071003&addnl=AR075&Add+to+charts=Add+to+charts&.cgifields=addnl Note how W3UGI (AR075) data (occassionally) have the impact of making the MADIS QCMS dew point and RH analysis go south. Hopefully MikeB will filter W3UGI RH/DewPoint from the analysis and solve your problem. I recently noticed my VP Pro2 Wireless (6153) ISS temperature/RH/rain gauge blinking out during the non-daylight periods. See here: http://www.findu.com/cgi-bin/wxpage.cgi?&call=CW0350&last=240 The ISS battery is the stock as shipped with the unit last April 2007. Seems odd that the battery would not hold the charge from the solar panel after only 6 months (still getting good light during the day). Thoughts? Thanks, Dave CW0351 Gary Ferdinand wrote: >OK, Richard. It was a wild idea to start with :-) I'm sure Davis knows best. > >My logic was that we have (here in NY) much less daylight hours and >those that exist have less solarization. Wx is more cloudy now further >reducing solarization. So it's not a stretch to me to speculate that >over a period when lower solar panel output existed, the cap might need >recharging from the battery. But, it's also colder now, and at night, >and that can greatly reduce available battery voltage. > >I had some similar problems a couple weeks ago, replaced the battery, >and all is well. YMMV. > >Good luck and 73, > >Gary W2CS ;-) > > > >Richard wrote: > > >>I found out from the Davis techs that the ISS doesn't use the battery >>at night, it actually uses a capacitor, charged during daylight, to >>supply power at night. It takes many hours to discharge it during >>normal use; I know because I replaced a transmitter board on mine and >>the old one was still happily transmitting well over twelve hours >>later. Only when the Cap is discharged, does it use the backup battery. >>*Richard* >>*www.n7tgb.net* >> >>------------------------------------------------------------------------ >>*From:* wxqc-bounces at lists.gladstonefamily.net >>[mailto:wxqc-bounces at lists.gladstonefamily.net] *On Behalf Of *N3UJJ >>*Sent:* Tuesday, October 02, 2007 4:22 PM >>*To:* 'Discussion of weather data quality issues' >>*Subject:* Re: [wxqc] Do I have an Issue? >> >>Gary, >> >>Looks like you are right... >> >>Here is an hourly graph on my reception: >>http://weather.n3ujj.com/hour/ReceptionHistory.gif you can see it drop >>at night, and it only seems to have started since the weather has cooled. >> >>This unit is 3 months old, who would think it should have a battery >>problem so soon. >> >>Let?s see what Davis is going to have to say about this (smile) >> >>*Scott Gillis (N3UJJ)* >> >>/My Current Location / >> >>/My Weather Station / >> >>-----Original Message----- >>From: wxqc-bounces at lists.gladstonefamily.net >>[mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Gary >>Ferdinand >>Sent: Tuesday, October 02, 2007 5:48 PM >>To: Discussion of weather data quality issues >>Subject: Re: [wxqc] Do I have an Issue? >> >>John, >> >>Just a thought but how strong is your battery? Perhaps it no longer is >> >>capable of supplying sufficient power at night. During the day the solar >> >>cells do the trick. Try a strip chart on the ISS signal and see if >> >>there's anything to be learned. Good luck >> >>Gary >> >>JOHN HARKNESS wrote: >> >> >> >>>I have had my weather station (Davis ProVantage2) for nearly a year >>> >>> >>>now, and have had no problems. Over the past couple of weeks, I have >>> >>> >>>noticed a drop in my quality control graphs during the nightime hours >>> >>> >>>in temp and then it is greater during the day. I thought I had siting >>> >>> >>>problems with the station, so I reverted back to the recommended >>> >>> >>>siting guidelines from Davis. There was no change in trend. My reading >>> >>> >>>are very close to the nearby stations in FindU >>> >>> >>> but are >>> >>> >>>horrendously different from the readings I was close to from nearby >>> >>> >>>stations on weatherunderground.. I don?t want to make changes if I >>> >>> >>>don?t need to, but would like to stay accurate. My CWOP >>> >>> >>> readings have also >>> >>> >>>gone awry. I don?t know if that is because of new stations or not. Any >>> >>> >>>help would be greatly appreciated. >>> >>> >>>John >>> >>> >>>john at horshamweather.com >>> >>> >>>www.horshamweather.com >>> >>> >>>------------------------------------------------------------------------ >>> >>> >>>_______________________________________________ >>> >>> >>>wxqc mailing list >>> >>> >>>Post messages to wxqc at lists.gladstonefamily.net >>> >>> >>>To unsubcribe or change delivery options, please go to: >>> >>> >>>http://server.gladstonefamily.net/mailman/listinfo/wxqc >>> >>> >>>The contents of this message are the responsibility of the author. >>> >>> >>_______________________________________________ >> >>wxqc mailing list >> >>Post messages to wxqc at lists.gladstonefamily.net >> >>To unsubcribe or change delivery options, please go to: >> >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >>------------------------------------------------------------------------ >> >>_______________________________________________ >>wxqc mailing list >>Post messages to wxqc at lists.gladstonefamily.net >>To unsubcribe or change delivery options, please go to: >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From jjames at jameshillfarm.com Tue Oct 2 23:09:07 2007 From: jjames at jameshillfarm.com (John James) Date: Tue, 02 Oct 2007 21:09:07 -0700 Subject: [wxqc] Do I have an Issue? In-Reply-To: <470311CE.2040409@comcast.net> References: <000a01c80537$5a51ce70$6401a8c0@Home> <4702BCAB.804@taconic.net> <04e301c8055b$2263ae60$0501a8c0@Richardn> <4702FE4C.7090200@taconic.net> <470311CE.2040409@comcast.net> Message-ID: <200710030409.l9349QB4081430@jameshillfarm.com> I'm wondering if you're under the same misconception I was. I always assumed the battery got charged by the panels, but it doesn't. As someone else pointed out, the system runs off a combination of the panel and an internal capacitor, and only draws from the battery if the capacitor runs dry. If that happens, you run on battery power until the sun comes up and starts replenishing the capacitor. The battery you use is not a rechargeable battery. One of my two units has failed because the transmitting board needs replacing. I don't know what's gone wrong, but I replaced the battery and I still was going off the air in the wee hours of the morning. It doesn't want to draw from the battery when all else fails. I have a new board here, but the station is up at another location I visit sporadically. //John At 08:51 PM 10/2/2007, you wrote: >I recently noticed my VP Pro2 Wireless (6153) ISS temperature/RH/rain >gauge blinking out during the non-daylight periods. See here: >http://www.findu.com/cgi-bin/wxpage.cgi?&call=CW0350&last=240 > >The ISS battery is the stock as shipped with the unit last April 2007. >Seems odd that the battery would not hold the charge from the solar >panel after only 6 months (still getting good light during the day). >Thoughts? > >Thanks, > >Dave >CW0351 > --------------------------------------------------------------- John James mail: jjames at jameshillfarm.com Current weather: http://www.jameshillfarm.com/images/WeatherStripJamesHillFarm.jpg From kdmiller at oldsgmail.com Wed Oct 3 00:16:18 2007 From: kdmiller at oldsgmail.com (Keith Miller) Date: Wed, 03 Oct 2007 01:16:18 -0400 Subject: [wxqc] Do I have an Issue? In-Reply-To: <200710030409.l9349QB4081430@jameshillfarm.com> Message-ID: <275346AE5DE440559714412B1EB7999D@sauron> > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of John James > Sent: Wednesday, October 03, 2007 12:09 AM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Do I have an Issue? > > > I'm wondering if you're under the same misconception I was. I always > assumed the battery got charged by the panels, but it doesn't. As > someone else pointed out, the system runs off a combination of the > panel and an internal capacitor, and only draws from the battery if > the capacitor runs dry. If that happens, you run on battery power > until the sun comes up and starts replenishing the capacitor. The > battery you use is not a rechargeable battery. > It's a Lithium battery, which works better when cold, but isn't rechargable. So, that's correct. The battery is just backup power for after solar and the "super cap" runs out. Keith -- CW5250 => http://weather.stadhaugh.com From ken at ubh.com Wed Oct 3 08:30:25 2007 From: ken at ubh.com (Ken Whelan) Date: Wed, 3 Oct 2007 08:30:25 -0500 Subject: [wxqc] Do I have an Issue? In-Reply-To: <275346AE5DE440559714412B1EB7999D@sauron> References: <200710030409.l9349QB4081430@jameshillfarm.com> <275346AE5DE440559714412B1EB7999D@sauron> Message-ID: <4C7058FCA5307C4BBE440C692631B127C06B64@pig.uhc.cc> One thing to note: For those of you digging around in the Davis, please be very careful of touching the terminals on the capacitor. Unlike a battery, a capacitor is capable of releasing all of the stored energy at once. You want to make sure that the stored energy is not released into your body as that kind of jolt is particularly hard on your heart. I have not been into the Davis, so I don't know how big that capacitor actually is but if it is of much size at all be very careful with it. kw -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Keith Miller Sent: Wednesday, October 03, 2007 12:16 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Do I have an Issue? > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of John James > Sent: Wednesday, October 03, 2007 12:09 AM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Do I have an Issue? > > > I'm wondering if you're under the same misconception I was. I always > assumed the battery got charged by the panels, but it doesn't. As > someone else pointed out, the system runs off a combination of the > panel and an internal capacitor, and only draws from the battery if > the capacitor runs dry. If that happens, you run on battery power > until the sun comes up and starts replenishing the capacitor. The > battery you use is not a rechargeable battery. > It's a Lithium battery, which works better when cold, but isn't rechargable. So, that's correct. The battery is just backup power for after solar and the "super cap" runs out. Keith -- CW5250 => http://weather.stadhaugh.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From slottech at gbis.com Wed Oct 3 08:34:34 2007 From: slottech at gbis.com (Richard) Date: Wed, 3 Oct 2007 06:34:34 -0700 Subject: [wxqc] Do I have an Issue? In-Reply-To: <4C7058FCA5307C4BBE440C692631B127C06B64@pig.uhc.cc> References: <200710030409.l9349QB4081430@jameshillfarm.com><275346AE5DE440559714412B1EB7999D@sauron> <4C7058FCA5307C4BBE440C692631B127C06B64@pig.uhc.cc> Message-ID: <055501c805c2$23263540$0501a8c0@Richardn> It is very low voltage. Richard www.n7tgb.net -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Ken Whelan Sent: Wednesday, October 03, 2007 6:30 AM To: Discussion of weather data quality issues Subject: Re: [wxqc] Do I have an Issue? One thing to note: For those of you digging around in the Davis, please be very careful of touching the terminals on the capacitor. Unlike a battery, a capacitor is capable of releasing all of the stored energy at once. You want to make sure that the stored energy is not released into your body as that kind of jolt is particularly hard on your heart. I have not been into the Davis, so I don't know how big that capacitor actually is but if it is of much size at all be very careful with it. kw -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Keith Miller Sent: Wednesday, October 03, 2007 12:16 AM To: 'Discussion of weather data quality issues' Subject: Re: [wxqc] Do I have an Issue? > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of John James > Sent: Wednesday, October 03, 2007 12:09 AM > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Do I have an Issue? > > > I'm wondering if you're under the same misconception I was. I always > assumed the battery got charged by the panels, but it doesn't. As > someone else pointed out, the system runs off a combination of the > panel and an internal capacitor, and only draws from the battery if > the capacitor runs dry. If that happens, you run on battery power > until the sun comes up and starts replenishing the capacitor. The > battery you use is not a rechargeable battery. > It's a Lithium battery, which works better when cold, but isn't rechargable. So, that's correct. The battery is just backup power for after solar and the "super cap" runs out. Keith -- CW5250 => http://weather.stadhaugh.com _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From N3UJJ at N3UJJ.COM Wed Oct 3 10:02:05 2007 From: N3UJJ at N3UJJ.COM (N3UJJ) Date: Wed, 3 Oct 2007 11:02:05 -0400 Subject: [wxqc] Errors on Davis Wireless Units ????? In-Reply-To: References: <000a01c80537$5a51ce70$6401a8c0@Home> <00c901c80548$d55a53b0$800efb10$@COM><04de01c8055a$5805cdb0$0501a8c0@Richardn> Message-ID: Well so much for the thought that the Rig Control computer was causing interference Here is the last 12 hours of reception: http://weather.n3ujj.com/hour/ReceptionHistory.gif Here is the last 24 hours of reception: http://weather.n3ujj.com/day/ReceptionHistory.gif I turned off the computer at 10:30 last night Scott Gillis N3UJJ My Current Location My Amateur Weather Station _____ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071003/1330a769/attachment.html From JHARKNESS373 at COMCAST.NET Wed Oct 3 14:11:17 2007 From: JHARKNESS373 at COMCAST.NET (JOHN HARKNESS) Date: Wed, 3 Oct 2007 15:11:17 -0400 Subject: [wxqc] do I have an issue? In-Reply-To: Message-ID: <000d01c805f1$2d1cd2a0$6401a8c0@Home> First off, I want to thank everyone who has responded to my worries!! This is a great tool for all of us! I noticed that last night, as the temperature stayed somewhat mild, that my overnight temps were much better. I guess 'it is what it is' . And as someone responded before, the fun part is going to be finding out what it is. I will keep you posted. John john at horshamweather.com www.horshamweather.com From brillig at gmail.com Wed Oct 3 14:38:33 2007 From: brillig at gmail.com (Victor Engel) Date: Wed, 3 Oct 2007 14:38:33 -0500 Subject: [wxqc] Sling Psychrometer Message-ID: All, One of the things on my to-do list is to get a sling psychrometer. Since the purpose of getting one is to calibrate my other equipment, I'd like to get one that's reasonably accurate and precise. That being said, I don't want to pay an arm and a leg if I don't have to. Can anyone recommend a good source? Victor From gmilatz at chartermi.net Wed Oct 3 16:37:58 2007 From: gmilatz at chartermi.net (Greg) Date: Wed, 3 Oct 2007 17:37:58 -0400 Subject: [wxqc] Sling Psychrometer References: Message-ID: <001a01c80605$aab74600$0201a8c0@milatzg> Try Ben Meadows company. They sell great quality outdoor/forestry type gear and tools as well as weather equipment. I have seen sling psychro's in their catalog. They are on-line at www.benmeadows.com Visit my website at........ www.newportmi.com ----- Original Message ----- From: "Victor Engel" To: "Discussion of weather data quality issues" Sent: Wednesday, October 03, 2007 3:38 PM Subject: [wxqc] Sling Psychrometer > All, > > One of the things on my to-do list is to get a sling psychrometer. > Since the purpose of getting one is to calibrate my other equipment, > I'd like to get one that's reasonably accurate and precise. That being > said, I don't want to pay an arm and a leg if I don't have to. Can > anyone recommend a good source? > > Victor > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. From jimwc at frontiernet.net Wed Oct 3 16:41:01 2007 From: jimwc at frontiernet.net (Jim) Date: Wed, 3 Oct 2007 14:41:01 -0700 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: <000001c80606$17e6a0e0$47b3e2a0$@net> Victor I got mine through Ben Meadows www.benmeadows.com prices range from +- $40.00 to +- 120.00 Jim CW4367 -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Victor Engel Sent: Wednesday, October 03, 2007 12:39 PM To: Discussion of weather data quality issues Subject: [wxqc] Sling Psychrometer All, One of the things on my to-do list is to get a sling psychrometer. Since the purpose of getting one is to calibrate my other equipment, I'd like to get one that's reasonably accurate and precise. That being said, I don't want to pay an arm and a leg if I don't have to. Can anyone recommend a good source? Victor _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From dmcintyre at att.net Wed Oct 3 15:52:30 2007 From: dmcintyre at att.net (Dexter McIntyre W4DEX) Date: Wed, 03 Oct 2007 16:52:30 -0400 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: <4704010E.9020806@att.net> Victor Engel wrote: > One of the things on my to-do list is to get a sling psychrometer. > Since the purpose of getting one is to calibrate my other equipment, > I'd like to get one that's reasonably accurate and precise. That being > said, I don't want to pay an arm and a leg if I don't have to. Can > anyone recommend a good source? Make one. All you need is two thermometers. Wrap the bulb of one with cloth and expose to fast moving air. I have a high dollar sling psycohrometer but have found the homebrew one to be just as accurate. Dexter From brillig at gmail.com Wed Oct 3 17:29:36 2007 From: brillig at gmail.com (Victor Engel) Date: Wed, 3 Oct 2007 17:29:36 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: <4704010E.9020806@att.net> References: <4704010E.9020806@att.net> Message-ID: Speaking of wind, I always thought that there may be an acceleration issue with sling psychrometers. Wouldn't it be better to blow the air on the bulb rather than slinging it around? But I guess since the liquid is incompressible, it doesn't really matter. I used to have a dry/wet thermometer pair for the greenhouse. It was stationary, though, and didn't have a wind source other than the greenhouse fan. On 10/3/07, Dexter McIntyre W4DEX wrote: > Victor Engel wrote: > > > One of the things on my to-do list is to get a sling psychrometer. > > Since the purpose of getting one is to calibrate my other equipment, > > I'd like to get one that's reasonably accurate and precise. That being > > said, I don't want to pay an arm and a leg if I don't have to. Can > > anyone recommend a good source? > > Make one. All you need is two thermometers. Wrap the bulb > of one with cloth and expose to fast moving air. I have a > high dollar sling psycohrometer but have found the homebrew > one to be just as accurate. > > Dexter > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From deadeye916 at gmail.com Wed Oct 3 16:11:11 2007 From: deadeye916 at gmail.com (Dan Crooks) Date: Wed, 3 Oct 2007 14:11:11 -0700 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: Victor, Here's my recommendation (get it with NIST certification) http://www.extech.com/instrument/products/alpha/RH390Psych.html Makes it easy to calibrate your other instruments. Totally digital and fool-proof (I needed that). Dan On 10/3/07, Victor Engel wrote: > > All, > > One of the things on my to-do list is to get a sling psychrometer. > Since the purpose of getting one is to calibrate my other equipment, > I'd like to get one that's reasonably accurate and precise. That being > said, I don't want to pay an arm and a leg if I don't have to. Can > anyone recommend a good source? > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071003/d6d5ab10/attachment.html From brillig at gmail.com Wed Oct 3 18:18:19 2007 From: brillig at gmail.com (Victor Engel) Date: Wed, 3 Oct 2007 18:18:19 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: Is +/- 2-4% really what I can expect for a precision instrument? Victor On 10/3/07, Dan Crooks wrote: > Victor, > > Here's my recommendation (get it with NIST certification) > > http://www.extech.com/instrument/products/alpha/RH390Psych.html > > Makes it easy to calibrate your other instruments. Totally digital and > fool-proof (I needed that). > > > Dan > > > > On 10/3/07, Victor Engel wrote: > > All, > > > > One of the things on my to-do list is to get a sling psychrometer. > > Since the purpose of getting one is to calibrate my other equipment, > > I'd like to get one that's reasonably accurate and precise. That being > > said, I don't want to pay an arm and a leg if I don't have to. Can > > anyone recommend a good source? > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From tbirk at clover.net Wed Oct 3 19:10:02 2007 From: tbirk at clover.net (Tim Birkeland) Date: Wed, 03 Oct 2007 20:10:02 -0400 Subject: [wxqc] Sling Psychrometer Message-ID: <47042F5A.8060005@clover.net> I got my sling psychrometer for Novalynx: http://www.novalynx.com/ Price was $90 for a NWS type. part # 225-570. Tim Birkeland Waterford, OH CW6969 From cbelldina at mywinchester.org Wed Oct 3 22:07:50 2007 From: cbelldina at mywinchester.org (Craig A. Belldina) Date: Wed, 3 Oct 2007 23:07:50 -0400 Subject: [wxqc] weather quality report problem?? Message-ID: <003401c80633$c0154fa0$403feee0$@org> I'm new to these weather quality reports, but I am assuming my temp. gauge is reporting slightly colder than expected? Any insight, thoughts are appreciated! DATE UTC * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 03-OCT-2007 Errs * 0/96 * 1/96 * 0/96 * 0/96 * 0/96 Note that times are in UTC. The values displayed are 'Observed (error)' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. You have to pick out the reading that is in error. The row with the time of 'Smry' is a daily summary and the data is 'mean(standard deviation)' for each observation during that day. Graphs: http://weather.gladstonefamily.net/qchart/C8713?date=20071004 -Craig ========================= Craig A. Belldina MyWinchester.org (Live Weather & Info!) ~Member~ NWS/NOAA Skywarn Certified Storm Spotter ~ WCC02 Citizens Weather Observation Program (CWOP) ~ CW8713 Weather Underground ~ Station ID # KVAWINCH12 CoCoRaHS Station # VA-WNC-1 cbelldina at mywinchester.org www.BeeCertain.com LOCATION ~ Lat. 39.18 ~ LON. -78.17 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071003/1b515385/attachment.html From dshelms at comcast.net Wed Oct 3 23:30:46 2007 From: dshelms at comcast.net (Dave Helms) Date: Thu, 04 Oct 2007 00:30:46 -0400 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: <47046C76.6080007@comcast.net> Hi Victor, Anything less than 5% error is good. I got my sling from Ebay: http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=sling+psychrometer&category0= Taylors and Bacharach slings are pretty good. I think I brought my Taylor for $25 from Ebay. Dave CW0351 Victor Engel wrote: >Is +/- 2-4% really what I can expect for a precision instrument? > >Victor > >On 10/3/07, Dan Crooks wrote: > > >>Victor, >> >>Here's my recommendation (get it with NIST certification) >> >>http://www.extech.com/instrument/products/alpha/RH390Psych.html >> >>Makes it easy to calibrate your other instruments. Totally digital and >>fool-proof (I needed that). >> >> >>Dan >> >> >> >>On 10/3/07, Victor Engel wrote: >> >> >>>All, >>> >>>One of the things on my to-do list is to get a sling psychrometer. >>>Since the purpose of getting one is to calibrate my other equipment, >>>I'd like to get one that's reasonably accurate and precise. That being >>>said, I don't want to pay an arm and a leg if I don't have to. Can >>>anyone recommend a good source? >>> >>> >>> >>_______________________________________________ >>wxqc mailing list >>Post messages to wxqc at lists.gladstonefamily.net >>To unsubcribe or change delivery options, please go to: >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >> >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From brillig at gmail.com Wed Oct 3 23:33:45 2007 From: brillig at gmail.com (Victor Engel) Date: Wed, 3 Oct 2007 23:33:45 -0500 Subject: [wxqc] weather quality report problem?? In-Reply-To: <003401c80633$c0154fa0$403feee0$@org> References: <003401c80633$c0154fa0$403feee0$@org> Message-ID: On the contrary, it looks like your station is warmer than expected during the day. One thing I like to do is to select the checkboxes for other nearby stations. Over time, I get to know the nuances of my neighboring stations and can tell if the "problem" is with my station or theirs. Don't assume the analysis is correct. It's usually a very good starting point. From there, you have to take your local situation into account. Microclimates can play a significant role. That being said, I'd bet you have some daytime heating due to exposure to the sun -- especially if you don't have a fan-aspirated shelter. If you click on the summary page, you will usually get suggestions for what might be wrong. Also, review the siting guidelines also available as a link from the summary page. On 10/3/07, Craig A. Belldina wrote: > > > > > > I'm new to these weather quality reports, but I am assuming my temp. gauge > is reporting slightly colder than expected? Any insight, thoughts are > appreciated! > > DATE UTC * ALT * POT TEMP * DEW PNT * DD * FF > * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) > 03-OCT-2007 Errs * 0/96 * 1/96 * 0/96 * 0/96 * 0/96 > > Note that times are in UTC. The values displayed are 'Observed (error)' > The error value is 'analysis - observed'. I.e. if your observed value is > higher > than the computed value, then the error will be negative. You have to pick > out > the reading that is in error. The row with the time of 'Smry' is a daily > summary > and the data is 'mean(standard deviation)' for each observation during > that day. > > Graphs: > http://weather.gladstonefamily.net/qchart/C8713?date=20071004 > > -Craig > > > > ========================= > > Craig A. Belldina > > MyWinchester.org (Live Weather & Info!) > > ~Member~ > > NWS/NOAA Skywarn Certified Storm Spotter ~ WCC02 > > Citizens Weather Observation Program (CWOP) ~ CW8713 > > Weather Underground ~ Station ID # KVAWINCH12 > > CoCoRaHS Station # VA-WNC-1 > > cbelldina at mywinchester.org > > www.BeeCertain.com > > LOCATION ~ Lat. 39.18 ~ LON. -78.17 > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From dshelms at comcast.net Wed Oct 3 23:35:06 2007 From: dshelms at comcast.net (Dave Helms) Date: Thu, 04 Oct 2007 00:35:06 -0400 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <4704010E.9020806@att.net> Message-ID: <47046D7A.9050400@comcast.net> Victor, Slings are a good reference instrument for dew point and have been used for many years in meteorology. It doesn't matter how you get that wick to chill to the wet bulb temperature, be it by a fan or by mechanical aspiration (sling). Dave CW0351 Victor Engel wrote: >Speaking of wind, I always thought that there may be an acceleration >issue with sling psychrometers. Wouldn't it be better to blow the air >on the bulb rather than slinging it around? But I guess since the >liquid is incompressible, it doesn't really matter. > >I used to have a dry/wet thermometer pair for the greenhouse. It was >stationary, though, and didn't have a wind source other than the >greenhouse fan. > >On 10/3/07, Dexter McIntyre W4DEX wrote: > > >>Victor Engel wrote: >> >> >> >>>One of the things on my to-do list is to get a sling psychrometer. >>>Since the purpose of getting one is to calibrate my other equipment, >>>I'd like to get one that's reasonably accurate and precise. That being >>>said, I don't want to pay an arm and a leg if I don't have to. Can >>>anyone recommend a good source? >>> >>> >>Make one. All you need is two thermometers. Wrap the bulb >>of one with cloth and expose to fast moving air. I have a >>high dollar sling psycohrometer but have found the homebrew >>one to be just as accurate. >> >>Dexter >>_______________________________________________ >>wxqc mailing list >>Post messages to wxqc at lists.gladstonefamily.net >>To unsubcribe or change delivery options, please go to: >>http://server.gladstonefamily.net/mailman/listinfo/wxqc >> >>The contents of this message are the responsibility of the author. >> >> >> >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From dshelms at comcast.net Wed Oct 3 23:45:11 2007 From: dshelms at comcast.net (Dave Helms) Date: Thu, 04 Oct 2007 00:45:11 -0400 Subject: [wxqc] weather quality report problem?? In-Reply-To: <003401c80633$c0154fa0$403feee0$@org> References: <003401c80633$c0154fa0$403feee0$@org> Message-ID: <47046FD7.70402@comcast.net> Hi Craig, Only one (1) "flag" for 96 reports is pretty good. Looking at your station page and pictures: http://weather.gladstonefamily.net/site/C8713 ... It looks like your temperature is running a 3-5F warmer than the analysis at the time of maximum temperature. Is your temperature sensor in the little white box labeled "Oregon Scientific"? Could be that your temperature sensor could use improved aspiration, although your temperature observations are generally very good outside of max temperature. More info on shielding option here: http://www.wxqa.com/shields.html Dave CW0351 Craig A. Belldina wrote: > I?m new to these weather quality reports, but I am assuming my temp. > gauge is reporting slightly colder than expected? Any insight, > thoughts are appreciated! > > DATE UTC * ALT * POT TEMP * DEW PNT * DD * FF > * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) > 03-OCT-2007 Errs * 0/96 * 1/96 * 0/96 * 0/96 * 0/96 > > Note that times are in UTC. The values displayed are 'Observed (error)' > The error value is 'analysis - observed'. I.e. if your observed value > is higher > than the computed value, then the error will be negative. You have to > pick out > the reading that is in error. The row with the time of 'Smry' is a > daily summary > and the data is 'mean(standard deviation)' for each observation during > that day. > > Graphs: http://weather.gladstonefamily.net/qchart/C8713?date=20071004 > > -Craig > > ========================= > > Craig A. Belldina > > */MyWinchester.org (Live Weather & Info!)/* > > *~Member~*** > > *NWS/NOAA **Skywarn Certified Storm Spotter ~ WCC02 > * > > *Citizens Weather Observation Program (CWOP) ~ CW8713 > * > > *Weather Underground ~ Station ID # KVAWINCH12 > * > > *CoCoRaHS Station # VA-WNC-1 * > > cbelldina at mywinchester.org > > *www.BeeCertain.com *** > > *LOCATION ~ Lat. 39.18 ~ LON. -78.17*** > >------------------------------------------------------------------------ > >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > From brillig at gmail.com Wed Oct 3 23:39:25 2007 From: brillig at gmail.com (Victor Engel) Date: Wed, 3 Oct 2007 23:39:25 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: <47046D7A.9050400@comcast.net> References: <4704010E.9020806@att.net> <47046D7A.9050400@comcast.net> Message-ID: On 10/3/07, Dave Helms wrote: > Victor, > > Slings are a good reference instrument for dew point and have been used > for many years in meteorology. It doesn't matter how you get that wick > to chill to the wet bulb temperature, be it by a fan or by mechanical > aspiration (sling). ... which brings up something. I've noticed many of the digital models are called sling psychrometers on the websites selling them. When I first saw this, I laughed. Now I'm wondering, are you supposed to wave those digital models around? They don't seem designed for that purpose. Victor From dshelms at comcast.net Wed Oct 3 23:59:49 2007 From: dshelms at comcast.net (Dave Helms) Date: Thu, 04 Oct 2007 00:59:49 -0400 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <4704010E.9020806@att.net> <47046D7A.9050400@comcast.net> Message-ID: <47047345.2070609@comcast.net> Hi Victor, I think those digital sensors are mostly used in the HVAC industry. I actually do have a digital probe that came in the surplus military Mobile Observing System (MOS) Kit I got off Ebay too (Ebay can be addictive!). I have used the sling and the probe and prefer the sling, but maybe I'm "old school". Dave CW0351 Victor Engel wrote: >On 10/3/07, Dave Helms wrote: > > >>Victor, >> >>Slings are a good reference instrument for dew point and have been used >>for many years in meteorology. It doesn't matter how you get that wick >>to chill to the wet bulb temperature, be it by a fan or by mechanical >>aspiration (sling). >> >> > >... which brings up something. I've noticed many of the digital models >are called sling psychrometers on the websites selling them. When I >first saw this, I laughed. Now I'm wondering, are you supposed to wave >those digital models around? They don't seem designed for that >purpose. > >Victor >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > > > > From cbelldina at mywinchester.org Wed Oct 3 23:53:53 2007 From: cbelldina at mywinchester.org (Craig A. Belldina) Date: Thu, 4 Oct 2007 00:53:53 -0400 Subject: [wxqc] FW: weather quality report problem?? Message-ID: <003a01c80642$90fa7380$b2ef5a80$@org> Hello everyone, It looks as if GoDaddy is blocking any responses to my question that I posted on the mailing list, Philip had this problem with GoDaddy when sending my data quality checks and he knows it's a know issue with them..another problem with GoDaddy I suppose...anyway, so if you have any comments about my wx problem below, please feel free to send them directly to me @ cbelldina at mywinchester.org Thanks!! -Craig From: Craig A. Belldina [mailto:cbelldina at mywinchester.org] Sent: Wednesday, October 03, 2007 11:08 PM To: 'wxqc at lists.gladstonefamily.net' Subject: weather quality report problem?? I'm new to these weather quality reports, but I am assuming my temp. gauge is reporting slightly WARMER than expected? Any insight, thoughts are appreciated! DATE UTC * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 03-OCT-2007 Errs * 0/96 * 1/96 * 0/96 * 0/96 * 0/96 Note that times are in UTC. The values displayed are 'Observed (error)' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. You have to pick out the reading that is in error. The row with the time of 'Smry' is a daily summary and the data is 'mean(standard deviation)' for each observation during that day. Graphs: http://weather.gladstonefamily.net/qchart/C8713?date=20071004 -Craig ========================= Craig A. Belldina MyWinchester.org (Live Weather & Info!) ~Member~ NWS/NOAA Skywarn Certified Storm Spotter ~ WCC02 Citizens Weather Observation Program (CWOP) ~ CW8713 Weather Underground ~ Station ID # KVAWINCH12 CoCoRaHS Station # VA-WNC-1 cbelldina at mywinchester.org www.BeeCertain.com LOCATION ~ Lat. 39.18 ~ LON. -78.17 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071004/90a683c7/attachment.html From edith.thornburg at verizon.net Thu Oct 4 05:17:14 2007 From: edith.thornburg at verizon.net (Edith) Date: Thu, 04 Oct 2007 05:17:14 -0500 (CDT) Subject: [wxqc] CW5985 down for a bit Message-ID: <5712483.6470401191493035097.JavaMail.root@vms227.mailsrvcs.net> well, I got home from work yesterday and noticed clocks blinking. We must have lost power. I have my dedicated tower plugged into a UPS/surge protector. I noticed it blinking at me. I can't turn it back on for anything, and there are NO reset switches/buttons anywhere to be found. The manual says a power supply problem. I think something is fried. It will be a while before I get a new computer too. I've been hoping to get a laptop for my sewing machine...now I need 2... And my sewing machine is due to come home from the doctors today too... timing... (at least it's right before Christmas, so there's hope :) ) Edith From sullivan238 at cox.net Thu Oct 4 07:16:12 2007 From: sullivan238 at cox.net (Jim Sullivan) Date: Thu, 4 Oct 2007 05:16:12 -0700 Subject: [wxqc] Sling Psychrometer In-Reply-To: Message-ID: Waving the digital probe will speed up a stable reading. Otherwise you must allow 5-15 minutes for natural air currents moving over the probe. You don't have to whip it around like a wet-wick rig, just keep air flowing. Using a fan to speed settling time is OK, provided the fan is not adding heat. Some small motors can raise the air temp. Avoid this by using the fan to draw air across the sensor, with the motor upstream. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Victor Engel Sent: Wednesday, October 03, 2007 21:39 To: Discussion of weather data quality issues Subject: Re: [wxqc] Sling Psychrometer On 10/3/07, Dave Helms wrote: > Victor, > > Slings are a good reference instrument for dew point and have been used > for many years in meteorology. It doesn't matter how you get that wick > to chill to the wet bulb temperature, be it by a fan or by mechanical > aspiration (sling). ... which brings up something. I've noticed many of the digital models are called sling psychrometers on the websites selling them. When I first saw this, I laughed. Now I'm wondering, are you supposed to wave those digital models around? They don't seem designed for that purpose. Victor _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From sooner44 at valornet.com Thu Oct 4 06:15:42 2007 From: sooner44 at valornet.com (sooner44 at valornet.com) Date: Thu, 4 Oct 2007 6:15:42 -0500 Subject: [wxqc] CW4378 Message-ID: <20071004111542.XKAE19750.ispmxmta05-srv.windstream.net@webmail-relay.alltel.net> I am out of town until Friday. Hope to get CW4378 back on line then. Richard From geilola at up.net Thu Oct 4 08:23:38 2007 From: geilola at up.net (geilola at up.net) Date: Thu, 4 Oct 2007 09:23:38 -0400 Subject: [wxqc] cw4865 down Message-ID: <200710041323.l94DNcdl028683@localhost.localdomain> cw4865 will be down till Oct 8. Gale Eilola From geilola at up.net Thu Oct 4 08:22:27 2007 From: geilola at up.net (geilola at up.net) Date: Thu, 4 Oct 2007 09:22:27 -0400 Subject: [wxqc] (no subject) Message-ID: <200710041322.l94DMRlY028610@localhost.localdomain> Cw4865 will be down till Oct. 8. -------------- next part -------------- A non-text attachment was scrubbed... Name: cw4865 down till Oct. 8 Type: application/octet-stream Size: 0 bytes Desc: not available Url : http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071004/eff69af9/attachment.obj From paulgrace at lookoutranch.com Thu Oct 4 11:44:33 2007 From: paulgrace at lookoutranch.com (Paul Grace) Date: Thu, 4 Oct 2007 09:44:33 -0700 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: Message-ID: <00f901c806a5$d819d040$0200a8c0@dell1500> I think you mean "drawing the air across the sensor with the motor downstream" (the sensor being upstream) -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Jim Sullivan Sent: Thursday, October 04, 2007 05:16 To: Discussion of weather data quality issues Subject: Re: [wxqc] Sling Psychrometer Waving the digital probe will speed up a stable reading. Otherwise you must allow 5-15 minutes for natural air currents moving over the probe. You don't have to whip it around like a wet-wick rig, just keep air flowing. Using a fan to speed settling time is OK, provided the fan is not adding heat. Some small motors can raise the air temp. Avoid this by using the fan to draw air across the sensor, with the motor upstream. Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Victor Engel Sent: Wednesday, October 03, 2007 21:39 To: Discussion of weather data quality issues Subject: Re: [wxqc] Sling Psychrometer On 10/3/07, Dave Helms wrote: > Victor, > > Slings are a good reference instrument for dew point and have been > used for many years in meteorology. It doesn't matter how you get > that wick to chill to the wet bulb temperature, be it by a fan or by > mechanical aspiration (sling). ... which brings up something. I've noticed many of the digital models are called sling psychrometers on the websites selling them. When I first saw this, I laughed. Now I'm wondering, are you supposed to wave those digital models around? They don't seem designed for that purpose. Victor _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From brillig at gmail.com Thu Oct 4 11:58:08 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 4 Oct 2007 11:58:08 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: <00f901c806a5$d819d040$0200a8c0@dell1500> References: <00f901c806a5$d819d040$0200a8c0@dell1500> Message-ID: You're right. I knew what he meant, and would have done that anyway. Phrased a different way, the idea is to draw the air away from the sensor with negative pressure rather than toward it with positive pressure. On 10/4/07, Paul Grace wrote: > I think you mean "drawing the air across the sensor with the motor > downstream" (the sensor being upstream) > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net] On Behalf Of Jim Sullivan > Sent: Thursday, October 04, 2007 05:16 > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Sling Psychrometer > > Waving the digital probe will speed up a stable reading. Otherwise you must > allow 5-15 minutes for natural air currents moving over the probe. You don't > have to whip it around like a wet-wick rig, just keep air flowing. > > Using a fan to speed settling time is OK, provided the fan is not adding > heat. Some small motors can raise the air temp. Avoid this by using the fan > to draw air across the sensor, with the motor upstream. > > Jim Sullivan > > -----Original Message----- > From: wxqc-bounces at lists.gladstonefamily.net > [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Victor Engel > Sent: Wednesday, October 03, 2007 21:39 > To: Discussion of weather data quality issues > Subject: Re: [wxqc] Sling Psychrometer > > > On 10/3/07, Dave Helms wrote: > > Victor, > > > > Slings are a good reference instrument for dew point and have been > > used for many years in meteorology. It doesn't matter how you get > > that wick to chill to the wet bulb temperature, be it by a fan or by > > mechanical aspiration (sling). > > ... which brings up something. I've noticed many of the digital models are > called sling psychrometers on the websites selling them. When I first saw > this, I laughed. Now I'm wondering, are you supposed to wave those digital > models around? They don't seem designed for that purpose. > > Victor > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change > delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change > delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From lwood at mountainbase.com Thu Oct 4 13:29:08 2007 From: lwood at mountainbase.com (lwood at mountainbase.com) Date: Thu, 04 Oct 2007 11:29:08 -0700 Subject: [wxqc] Sling Psychrometer Message-ID: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071004/d6ab655f/attachment.html From cbelldina at gmail.com Thu Oct 4 12:44:05 2007 From: cbelldina at gmail.com (Craig A. Belldina) Date: Thu, 4 Oct 2007 13:44:05 -0400 Subject: [wxqc] WX station, warm temp readings.. Message-ID: <004501c806ae$295d5dc0$7c181940$@com> Not sure if this posted to the group before, Godaddy servers are blocking requests & it's a known problem with them..so I canceled and re-signed with a new email addy..hopefully this works..so here is my question.. I'm new to these weather quality reports, but I am assuming my temp. gauge is reporting slightly WARMER than expected? Any insight, thoughts are appreciated! I was thinking of covering the temp gauge with something? It's not fan aspirated...the unit is a OS WMR-100 USB. Also, the unit does get a lot of exposure. I am also taking into account I may be experiencing my own micro-climate. I am smack in the middle of Old Town Winchester, Va. ---------------------------------------------------------------------------- --------------- DATE UTC * ALT * POT TEMP * DEW PNT * DD * FF * (MB) * (DEG F) * (DEG F) * (DEG) * (KNT) 03-OCT-2007 Errs * 0/96 * 1/96 * 0/96 * 0/96 * 0/96 Note that times are in UTC. The values displayed are 'Observed (error)' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. You have to pick out the reading that is in error. The row with the time of 'Smry' is a daily summary and the data is 'mean(standard deviation)' for each observation during that day. Graphs: http://weather.gladstonefamily.net/qchart/C8713?date=20071004 Thanks!!! -Craig ========================= Craig A. Belldina MyWinchester.org (Live Weather & Info!) ~Member~ NWS/NOAA Skywarn Certified Storm Spotter ~ WCC02 Citizens Weather Observation Program (CWOP) ~ CW8713 Weather Underground ~ Station ID # KVAWINCH12 CoCoRaHS Station # VA-WNC-1 cbelldina at mywinchester.org www.BeeCertain.com LOCATION ~ Lat. 39.18 ~ LON. -78.17 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071004/bf2041dc/attachment.html From brillig at gmail.com Thu Oct 4 14:43:44 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 4 Oct 2007 14:43:44 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> Message-ID: I don't think it matters for manual slinging. The conversation started with motor driven air, where the motor could be heating the air. On the other hand, let's think about this a minute. The aerodynamics around the bulb could affect pressure, and evaporation rate is affected by pressure, so maybe it does make a difference. But how significant would the pressure change be? Small pressure changes are significant. To illustrate, I'll describe something my daughter (who just turned 21 today) showed me one time. She grabbed a mouthful of air and compressed it in her mouth as hard as possible, holding her breath as long as she could, thus allowing more water vapor to form in her mouth. After a minute or so, she opened her mouth to reveal some instant fog. Pretty cool trick. I mention this because I think the amount of pressure a human mouth can apply is very small. The only time I've ever tried to measure it was with a tire gauge, and I couldn't get the gauge to budge even to 1 PSI. I suppose I could see how high I can blow water up a tube. So the question is, does the pressure change around the bulb affect the evaporation? Then maybe slinging slowly is better than slinging quickly. Victor On 10/4/07, lwood at mountainbase.com wrote: > Ok, now you have me thinking(scary). Should I sling forwards to where the > air hits the wick straight on or backwards, drawing the air past. Never > would have thought there would be any difference or am I just reading > something into this subject that I shouldn't? > > Lance > CW1020 > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From ibbrunnie at comcast.net Thu Oct 4 14:57:17 2007 From: ibbrunnie at comcast.net (Rich Brunnworth) Date: Thu, 04 Oct 2007 13:57:17 -0600 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> Message-ID: <4705459D.70903@comcast.net> IIRC.... when we took our weather measurements up in Alaska at the AF radar station where I was, we twirled for a minute and then read the temps. Wonder what the instructions say. I seriously doubt that the "minor pressure differentials" have much of an effect on the accuracy of hte readings. Rich Victor Engel wrote: > I don't think it matters for manual slinging. The conversation started > with motor driven air, where the motor could be heating the air. > > On the other hand, let's think about this a minute. The aerodynamics > around the bulb could affect pressure, and evaporation rate is > affected by pressure, so maybe it does make a difference. But how > significant would the pressure change be? > > Small pressure changes are significant. To illustrate, I'll describe > something my daughter (who just turned 21 today) showed me one time. > > She grabbed a mouthful of air and compressed it in her mouth as hard > as possible, holding her breath as long as she could, thus allowing > more water vapor to form in her mouth. After a minute or so, she > opened her mouth to reveal some instant fog. Pretty cool trick. I > mention this because I think the amount of pressure a human mouth can > apply is very small. The only time I've ever tried to measure it was > with a tire gauge, and I couldn't get the gauge to budge even to 1 > PSI. I suppose I could see how high I can blow water up a tube. > > So the question is, does the pressure change around the bulb affect > the evaporation? Then maybe slinging slowly is better than slinging > quickly. > > From brillig at gmail.com Thu Oct 4 15:14:28 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 4 Oct 2007 15:14:28 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: <4705459D.70903@comcast.net> References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> <4705459D.70903@comcast.net> Message-ID: How about an off-the-cuff calculation? The speed of air molecules at room temperature is about 500 m/s. Suppose you rather industriously sling the psychrometer at 4 revolutions per second. If it's a rather long 1-meter psychrometer, then, round numbers, the speed with respect to the psychrometer changes by about 12 m/s, or 2.4%. I realize aerodynamics doesn't work that way. I'm just trying to get a feel for the order of magnitude involved here. Victor On 10/4/07, Rich Brunnworth wrote: > IIRC.... when we took our weather measurements up in Alaska at the AF > radar station where I was, we twirled for a minute and then read the > temps. Wonder what the instructions say. > > I seriously doubt that the "minor pressure differentials" have much of > an effect on the accuracy of hte readings. > > Rich > > Victor Engel wrote: > > I don't think it matters for manual slinging. The conversation started > > with motor driven air, where the motor could be heating the air. > > > > On the other hand, let's think about this a minute. The aerodynamics > > around the bulb could affect pressure, and evaporation rate is > > affected by pressure, so maybe it does make a difference. But how > > significant would the pressure change be? > > > > Small pressure changes are significant. To illustrate, I'll describe > > something my daughter (who just turned 21 today) showed me one time. > > > > She grabbed a mouthful of air and compressed it in her mouth as hard > > as possible, holding her breath as long as she could, thus allowing > > more water vapor to form in her mouth. After a minute or so, she > > opened her mouth to reveal some instant fog. Pretty cool trick. I > > mention this because I think the amount of pressure a human mouth can > > apply is very small. The only time I've ever tried to measure it was > > with a tire gauge, and I couldn't get the gauge to budge even to 1 > > PSI. I suppose I could see how high I can blow water up a tube. > > > > So the question is, does the pressure change around the bulb affect > > the evaporation? Then maybe slinging slowly is better than slinging > > quickly. > > > > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > From brillig at gmail.com Thu Oct 4 15:19:46 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 4 Oct 2007 15:19:46 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> <4705459D.70903@comcast.net> Message-ID: I decided to google psychrometer aerodynamics and found this relevant tidbit: http://docs.lib.noaa.gov/rescue/mwr/055/mwr-055-09-0398.pdf 'The "Note on Psychrometry in a Wind Channel," by R. A. Watson Watt, describes experiments showing that the formula used in reduction of data from the ventilated psychrometer applies at air speeds of 25 to 40 meters a second without appreciable change of constants from those appropriate to a speed of 4.5 meters a second.' On 10/4/07, Victor Engel wrote: > How about an off-the-cuff calculation? The speed of air molecules at > room temperature is about 500 m/s. Suppose you rather industriously > sling the psychrometer at 4 revolutions per second. If it's a rather > long 1-meter psychrometer, then, round numbers, the speed with respect > to the psychrometer changes by about 12 m/s, or 2.4%. I realize > aerodynamics doesn't work that way. I'm just trying to get a feel for > the order of magnitude involved here. > > Victor > > On 10/4/07, Rich Brunnworth wrote: > > IIRC.... when we took our weather measurements up in Alaska at the AF > > radar station where I was, we twirled for a minute and then read the > > temps. Wonder what the instructions say. > > > > I seriously doubt that the "minor pressure differentials" have much of > > an effect on the accuracy of hte readings. > > > > Rich > > > > Victor Engel wrote: > > > I don't think it matters for manual slinging. The conversation started > > > with motor driven air, where the motor could be heating the air. > > > > > > On the other hand, let's think about this a minute. The aerodynamics > > > around the bulb could affect pressure, and evaporation rate is > > > affected by pressure, so maybe it does make a difference. But how > > > significant would the pressure change be? > > > > > > Small pressure changes are significant. To illustrate, I'll describe > > > something my daughter (who just turned 21 today) showed me one time. > > > > > > She grabbed a mouthful of air and compressed it in her mouth as hard > > > as possible, holding her breath as long as she could, thus allowing > > > more water vapor to form in her mouth. After a minute or so, she > > > opened her mouth to reveal some instant fog. Pretty cool trick. I > > > mention this because I think the amount of pressure a human mouth can > > > apply is very small. The only time I've ever tried to measure it was > > > with a tire gauge, and I couldn't get the gauge to budge even to 1 > > > PSI. I suppose I could see how high I can blow water up a tube. > > > > > > So the question is, does the pressure change around the bulb affect > > > the evaporation? Then maybe slinging slowly is better than slinging > > > quickly. > > > > > > > > _______________________________________________ > > wxqc mailing list > > Post messages to wxqc at lists.gladstonefamily.net > > To unsubcribe or change delivery options, please go to: > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > The contents of this message are the responsibility of the author. > > > From brillig at gmail.com Thu Oct 4 15:54:32 2007 From: brillig at gmail.com (Victor Engel) Date: Thu, 4 Oct 2007 15:54:32 -0500 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> <4705459D.70903@comcast.net> Message-ID: That document also has a lot of other interesting information, for example, experiments showing that hair hygrometers can be made to exceed 2% accuracy. I used to have a greenhouse for orchids. I used hair hygrometers for it. Other hygrometers can't take the high humidity very well. On 10/4/07, Victor Engel wrote: > I decided to google psychrometer aerodynamics and found this relevant tidbit: > http://docs.lib.noaa.gov/rescue/mwr/055/mwr-055-09-0398.pdf > > 'The "Note on Psychrometry in a Wind Channel," by R. A. Watson Watt, > describes experiments showing that the formula used in reduction of > data from the ventilated psychrometer applies at air speeds of 25 to > 40 meters a second without appreciable change of constants from those > appropriate to a speed of 4.5 meters a second.' > > On 10/4/07, Victor Engel wrote: > > How about an off-the-cuff calculation? The speed of air molecules at > > room temperature is about 500 m/s. Suppose you rather industriously > > sling the psychrometer at 4 revolutions per second. If it's a rather > > long 1-meter psychrometer, then, round numbers, the speed with respect > > to the psychrometer changes by about 12 m/s, or 2.4%. I realize > > aerodynamics doesn't work that way. I'm just trying to get a feel for > > the order of magnitude involved here. > > > > Victor > > > > On 10/4/07, Rich Brunnworth wrote: > > > IIRC.... when we took our weather measurements up in Alaska at the AF > > > radar station where I was, we twirled for a minute and then read the > > > temps. Wonder what the instructions say. > > > > > > I seriously doubt that the "minor pressure differentials" have much of > > > an effect on the accuracy of hte readings. > > > > > > Rich > > > > > > Victor Engel wrote: > > > > I don't think it matters for manual slinging. The conversation started > > > > with motor driven air, where the motor could be heating the air. > > > > > > > > On the other hand, let's think about this a minute. The aerodynamics > > > > around the bulb could affect pressure, and evaporation rate is > > > > affected by pressure, so maybe it does make a difference. But how > > > > significant would the pressure change be? > > > > > > > > Small pressure changes are significant. To illustrate, I'll describe > > > > something my daughter (who just turned 21 today) showed me one time. > > > > > > > > She grabbed a mouthful of air and compressed it in her mouth as hard > > > > as possible, holding her breath as long as she could, thus allowing > > > > more water vapor to form in her mouth. After a minute or so, she > > > > opened her mouth to reveal some instant fog. Pretty cool trick. I > > > > mention this because I think the amount of pressure a human mouth can > > > > apply is very small. The only time I've ever tried to measure it was > > > > with a tire gauge, and I couldn't get the gauge to budge even to 1 > > > > PSI. I suppose I could see how high I can blow water up a tube. > > > > > > > > So the question is, does the pressure change around the bulb affect > > > > the evaporation? Then maybe slinging slowly is better than slinging > > > > quickly. > > > > > > > > > > > _______________________________________________ > > > wxqc mailing list > > > Post messages to wxqc at lists.gladstonefamily.net > > > To unsubcribe or change delivery options, please go to: > > > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > > > > > The contents of this message are the responsibility of the author. > > > > > > From sullivan238 at cox.net Wed Oct 3 21:52:17 2007 From: sullivan238 at cox.net (Jim Sullivan) Date: Wed, 3 Oct 2007 19:52:17 -0700 Subject: [wxqc] Sling Psychrometer In-Reply-To: Message-ID: Unfortunately, accurate and precise instruments are costly. Even more costly is a calibration certificate. I like the Extech instruments, reasonable price for what you get. A calibration certificate is not really needed for hobby use. The instrument is very likely to be in spec as received. The cal cert is an expensive guarantee that the instrument is in spec. And the cert dies after one year. Digital instruments are pretty stable though. For a tale of woe regarding RH measurement, read this article. If should cure you of a high precision desire. http://www.veriteq.com/download/practical-RH-experiences.pdf Jim Sullivan -----Original Message----- From: wxqc-bounces at lists.gladstonefamily.net [mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Victor Engel Sent: Wednesday, October 03, 2007 12:39 To: Discussion of weather data quality issues Subject: [wxqc] Sling Psychrometer All, One of the things on my to-do list is to get a sling psychrometer. Since the purpose of getting one is to calibrate my other equipment, I'd like to get one that's reasonably accurate and precise. That being said, I don't want to pay an arm and a leg if I don't have to. Can anyone recommend a good source? Victor _______________________________________________ wxqc mailing list Post messages to wxqc at lists.gladstonefamily.net To unsubcribe or change delivery options, please go to: http://server.gladstonefamily.net/mailman/listinfo/wxqc The contents of this message are the responsibility of the author. From ibbrunnie at comcast.net Thu Oct 4 16:50:05 2007 From: ibbrunnie at comcast.net (Rich Brunnworth) Date: Thu, 04 Oct 2007 15:50:05 -0600 Subject: [wxqc] Sling Psychrometer In-Reply-To: References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> <4705459D.70903@comcast.net> Message-ID: <4705600D.9080909@comcast.net> So basically..... speed has no effect on the readings. That's the way I read what you are saying. Rich Victor Engel wrote: > I decided to google psychrometer aerodynamics and found this relevant tidbit: > http://docs.lib.noaa.gov/rescue/mwr/055/mwr-055-09-0398.pdf > > 'The "Note on Psychrometry in a Wind Channel," by R. A. Watson Watt, > describes experiments showing that the formula used in reduction of > data from the ventilated psychrometer applies at air speeds of 25 to > 40 meters a second without appreciable change of constants from those > appropriate to a speed of 4.5 meters a second.' > > From dshelms at comcast.net Thu Oct 4 21:55:16 2007 From: dshelms at comcast.net (Dave Helms) Date: Thu, 04 Oct 2007 22:55:16 -0400 Subject: [wxqc] Sling Psychrometer In-Reply-To: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> References: <20071004112908.b014af6efb42cca08111bb1cc252e7a0.bc1cad3859.wbe@email.secureserver.net> Message-ID: <4705A794.20809@comcast.net> Lance, The only guidance is to sling with your body facing into the wind, that way your body heat does not influence the measurement. Here is an old posts on this thread on : http://server.gladstonefamily.net/pipermail/wxqc/2005-December/003366.html http://server.gladstonefamily.net/pipermail/wxqc/2005-December/003363.html Dave CW0351 lwood at mountainbase.com wrote: > Ok, now you have me thinking(scary). Should I sling forwards to where > the air hits the wick straight on or backwards, drawing the air past. > Never would have thought there would be any difference or am I just > reading something into this subject that I shouldn't? > > Lance > CW1020 > >------------------------------------------------------------------------ > >_______________________________________________ >wxqc mailing list >Post messages to wxqc at lists.gladstonefamily.net >To unsubcribe or change delivery options, please go to: >http://server.gladstonefamily.net/mailman/listinfo/wxqc > >The contents of this message are the responsibility of the author. > From ejcobb at bellsouth.net Fri Oct 5 01:58:26 2007 From: ejcobb at bellsouth.net (ejcobb at bellsouth.net) Date: Fri, 05 Oct 2007 06:58:26 +0000 Subject: [wxqc] Sling Psychrometer Message-ID: <100520070658.8749.4705E092000388560000222D22230650629B0A02D2089B9A019C04040A0DBF0D0D010C060A@bellsouth.net> I borrowed one from the local National Weather Service station. They were happy to loan it to me. John CW6973 -------------- Original message from "Victor Engel" : -------------- > All, > > One of the things on my to-do list is to get a sling psychrometer. > Since the purpose of getting one is to calibrate my other equipment, > I'd like to get one that's reasonably accurate and precise. That being > said, I don't want to pay an arm and a leg if I don't have to. Can > anyone recommend a good source? > > Victor > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071005/e3676b97/attachment-0001.html From n8mni at columbus.rr.com Fri Oct 5 08:52:04 2007 From: n8mni at columbus.rr.com (Mark Crosbie) Date: Fri, 5 Oct 2007 09:52:04 -0400 Subject: [wxqc] error report? Message-ID: <003401c80756$ea47b910$0202a8c0@MARK> Please explain to me how this works and why my temp reading has errors. My temp/humidity sensor is mounted at about 12 feet up. It is also inside a pagoda style radiation shield. I have an OS wmr968 weather station. Mark Date UTC Alt (mb) Temp ?F DewPt ?F Wind Dir Speed knts 04-OCT-2007 1814 1021.6 -1.35 92 -6.52 52 +3.76 169 -44 2.6 -0.7 04-OCT-2007 1833 1021.6 -1.35 92 -6.52 53 +2.73 270 -145 2.6 -0.7 04-OCT-2007 1844 1021.6 -1.40 92 -6.52 53 +2.73 112 +13 2.6 -0.7 04-OCT-2007 1900 1021.6 -1.77 93 -6.59 53 +3.67 116 +5 2.6 +0.1 04-OCT-2007 1915 1021.6 -1.77 94 -7.59 53 +3.90 143 -22 1.7 +1.0 04-OCT-2007 2344 1020.6 -1.35 74 +6.18 55 -0.91 0 +120 0.0 +1.4 04-OCT-2007 Errs 15/94 11/94 1/94 0/94 0/94 04-OCT-2007 Smry -1.5 0.34 +1 4.31 +2 2.73 +42 56 +0.8 0.8 Note that times are in UTC. The values displayed are 'Observed Error' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. The error readings are listed in bold. The row with the time of 'Smry' is a daily summary and the data is 'mean standard-deviation' for each observation during that day. The 'Errs' row contains the number of samples in error / the number of samples (as seen by MADIS). This may indicate more observations that are shown above. This is due to the differing limits used by this reporting program and the MADIS program itself. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071005/cb19f60c/attachment.html From brillig at gmail.com Fri Oct 5 11:07:58 2007 From: brillig at gmail.com (Victor Engel) Date: Fri, 5 Oct 2007 11:07:58 -0500 Subject: [wxqc] error report? In-Reply-To: <003401c80756$ea47b910$0202a8c0@MARK> References: <003401c80756$ea47b910$0202a8c0@MARK> Message-ID: Heheh. Thanks for posting this. I was going to request a sample report with bolded errors, because I have not received any to date. I was afraid I was missing error reports. Now, thanks to your post, I can see that I actually can tell if something is bolded. What is your station ID? People can probably give you more informative information if they know what station they're talking about. Victor On 10/5/07, Mark Crosbie wrote: > > Please explain to me how this works and why my temp reading has errors. > My temp/humidity sensor is mounted at about 12 feet up. It is also inside a > pagoda style radiation shield. I have an OS wmr968 weather station. > Mark > > > > Date UTC Alt (mb) Temp ?F DewPt ?F Wind Dir Speed knts 04-OCT-2007 1814 > 1021.6 -1.35 *92* *-6.52* 52 +3.76 169 -44 2.6 -0.7 04-OCT-2007 1833 > 1021.6 -1.35 *92* *-6.52* 53 +2.73 270 -145 2.6 -0.7 04-OCT-2007 1844 > 1021.6 -1.40 *92* *-6.52* 53 +2.73 112 +13 2.6 -0.7 04-OCT-2007 1900 > 1021.6 -1.77 *93* *-6.59* 53 +3.67 116 +5 2.6 +0.1 04-OCT-2007 1915 1021.6 > -1.77 *94* *-7.59* 53 +3.90 143 -22 1.7 +1.0 04-OCT-2007 2344 1020.6 -1.35 > *74* *+6.18* 55 -0.91 0 +120 0.0 +1.4 04-OCT-2007 Errs 15/94 11/94 1/94 0/94 > 0/94 04-OCT-2007 Smry -1.5 0.34 +1 4.31 +2 2.73 +42 56 +0.8 0.8 > > Note that times are in UTC. The values displayed are 'Observed Error' The > error value is 'analysis - observed'. I.e. if your observed value is > higher than the computed value, then the error will be negative. The error > readings are listed in *bold*. The row with the time of 'Smry' is a daily > summary and the data is 'mean standard-deviation' for each observation > during that day. The 'Errs' row contains the number of samples in error / > the number of samples (as seen by MADIS). This may indicate more > observations that are shown above. This is due to the differing limits used > by this reporting program and the MADIS program itself. > > _______________________________________________ > wxqc mailing list > Post messages to wxqc at lists.gladstonefamily.net > To unsubcribe or change delivery options, please go to: > http://server.gladstonefamily.net/mailman/listinfo/wxqc > > The contents of this message are the responsibility of the author. > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://server.gladstonefamily.net/pipermail/wxqc/attachments/20071005/19957a24/attachment.html From n8mni at columbus.rr.com Fri Oct 5 11:28:03 2007 From: n8mni at columbus.rr.com (Mark Crosbie) Date: Fri, 5 Oct 2007 12:28:03 -0400 Subject: [wxqc] error report? References: <003401c80756$ea47b910$0202a8c0@MARK> Message-ID: <002701c8076c$b4cf3540$0202a8c0@MARK> AS737 ----- Original Message ----- From: Victor Engel To: Discussion of weather data quality issues Sent: Friday, October 05, 2007 12:07 PM Subject: Re: [wxqc] error report? Heheh. Thanks for posting this. I was going to request a sample report with bolded errors, because I have not received any to date. I was afraid I was missing error reports. Now, thanks to your post, I can see that I actually can tell if something is bolded. What is your station ID? People can probably give you more informative information if they know what station they're talking about. Victor On 10/5/07, Mark Crosbie wrote: Please explain to me how this works and why my temp reading has errors. My temp/humidity sensor is mounted at about 12 feet up. It is also inside a pagoda style radiation shield. I have an OS wmr968 weather station. Mark Date UTC Alt (mb) Temp ?F DewPt ?F Wind Dir Speed knts 04-OCT-2007 1814 1021.6 -1.35 92 -6.52 52 +3.76 169 -44 2.6 -0.7 04-OCT-2007 1833 1021.6 -1.35 92 -6.52 53 +2.73 270 -145 2.6 -0.7 04-OCT-2007 1844 1021.6 -1.40 92 -6.52 53 +2.73 112 +13 2.6 -0.7 04-OCT-2007 1900 1021.6 -1.77 93 -6.59 53 +3.67 116 +5 2.6 +0.1 04-OCT-2007 1915 1021.6 -1.77 94 -7.59 53 +3.90 143 -22 1.7 +1.0 04-OCT-2007 2344 1020.6 -1.35 74 +6.18 55 -0.91 0 +120 0.0 +1.4 04-OCT-2007 Errs 15/94 11/94 1/94 0/94 0/94 04-OCT-2007 Smry -1.5 0.34 +1 4.31 +2 2.73 +42 56 +0.8 0.8 Note that times are in UTC. The values displayed are 'Observed Error' The error value is 'analysis - observed'. I.e. if your observed value is higher than the computed value, then the error will be negative. The error readings are listed in bold. The row with the time of 'Smry' is a daily summary and the data is 'mean standard-deviation' for each observation during that day. The 'Errs' row contains the number of samples in error / the number of samples (as seen by MADIS). This may indicate more observations that are shown above. This is due to the differing limits u