[wxqc] CWOP Information for CW4490 (C4490) in Leander, TX US

[Victor Engel]

I'm going to answer your question specifically and then also raise a more
generic question.

First, it looks like your pressure reading is too low. I believe if your
mean error exceeds 2 millibars, you will get the message. When I first set
up my stations (C6155) in 2006, I noticed it tracked another stations AS425
very closely in all data points, including pressure. Although we tracked
closely, the analysis stated our readings were too low, so I made an
adjustment upwards. My stations has had good QC for pressure ever since.

I wonder, though, about something. All three of us use Davis Vantage Pro
hardware, and all three of us were too low by similar amounts. Do these
stations generally ship with a slight adjustment error? Could there be an
adjustment needed at the factory? Certainly, we can't determine this from
just three data points. I'm curious of others' experiences around the
country, though, with this hardware.

An alternative, of course, is that our hardware is correct and the analysis
is wrong. Were that to be the case, though, the airport would be too high. I
think that's unlikely, since aircraft rely on accurate altimeter readings to
navigate.

The other thing I've noticed but haven't spent time to check is that it
appears the error in my readings may be correlated to temperature -- the
higher the temperature the lower my reading with respect to the analysis. I
may just be imagining that, and the magnitude of the effect certainly isn't
large, if present. If this really is true, though, I wonder what would cause
it.

Victor C6155

On Sun, Jun 1, 2008 at 6:56 AM, JBothne <jbothne at austin.rr.com> wrote:

>
> I'm looking for assistance or direction related to the MADIS analysis of my
> barometric pressure readings.  I have the Vantage 2 Pro unit and have been
> uploading data since installing the unit in Oct 2005.  My readings have
> always shown the same variants as compared to other stations and have
> remained consistent during this time.  As of recent I have been receiveing
> "MADIS rating Sensor fails L2 statistical
>
> consistency check " yet nothing has changed.  I am looking for advice and
> or direction to either resolve the issue or determine if the readings or a
> result of my geographical location in relation to other site.
>
> Regards,
> Joe
> *Cordially,*
> *Joseph A. Bothne*****
> *Hm: 512-259-8476*
> *Fax: 512.259.8781*
> ***mailto:jbothne at austin.rr.com* <jbothne at austin.rr.com>********
> *Homepage: **http://home.austin.rr.com/thebearcave/*<http://home.austin.rr.com/thebearcave/>
> **
>
> _______________________________________________
> 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
> To search the archives:
> http://www.google.com/coop/cse?cx=008314629403309390388%3Aknlfnptih9u
>
> 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/20080601/322f29d8/attachment-0001.html