[wxsig] Quality of instruments?

[Gerry Creager]

There are several issues one should look at with regard to instrument 
quality.

1.  With mechanical anemometry, one needs to look at the inertia 
associated with starting the cup or propeller.  If the bearing(s) get(s) 
sticky, windspeed and direction will suffer.  There were problems 
several years ago with Peet Bros. anemometers that I recall, and I also 
recall Peet spending a lot to take care of those in replacements.
2.  Inter-instrument reproducibility of measurements (inter-instrument 
variablilty) is an issue for some of us who look at the QA/QC of the 
APRS and CWOP networks.  A lot of the professional world is now starting 
to appreciate the increased densification offered by APRS-Wx and CWOP, 
and are using the data.  If there are problems resolving reproducible 
numbers for temp, pressure or humidity (or, for that matter, wind), then 
the numbers become suspect.  Some of the NOAA QC processing catches some 
of these trends and tendencies.  Some get missed.
3.  The resolution of most of these instruments isn't the same as the 
"professional" instrumentation.  That said, if it's reproducible it's 
certainly still usable.
4.  VERY IMPORTANT:  Please get the siting guide and white paper from 
http://mywebpages.comcast.net/dshelms/CWOP_Guide.pdf, and look at the 
resources page at:  http://www.wxqa.com/resources.html
There's LOTS of good information there.  Siting is the greatest concern 
we have with respect to getting good data.

73, gerry

Bogdan, Rick wrote:
> Hi Mike,
> 
> My AAG wx station has been up for over 4 years without any problems.
> 
> Rick ka1udx
> http://webpages.ursinus.edu/ka1udx
> 
> 
> -----Original Message-----
> From: Mike B [mailto:kw1nd at comcast.net] 
> Sent: Wednesday, November 09, 2005 16:14
> To: wxsig at lists.tapr.org
> Subject: [wxsig] Quality of instruments?
> 
> Greetings, all.  I'm new to the list, and am in the process of researching
> various home weather station systems.  The 1-wire system looks intriguing,
> as does the APRS functionality from TAPR.
> 
> Poor reviews on the quality of instruments is what turned me off the "mass
> market" systems from Oregon Scientific & LaCrosse.
> 
> How do the instruments from AAG hold up?
> --
> 73,
> Mike Boice, KW1ND
> Karns, TN
> Behold the power of the penguin
> Reclaim Your Inbox!  http://www.mozilla.org/products/thunderbird/
> 
> 
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-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
Cell: 979.229.5301 Office: 979.458.4020
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