On Thu, 01 Jan 2015 11:41:23 -0800, Jeff Liebermann
wrote:
Blundering onward...
Siting:
https://www.campbellsci.com/weather-station-siting
ftp://ftp.campbellsci.com/pub/outgoing/apnotes/siting.pdf
http://wxqa.com/resources.html
This one is quite good on siteing.
http://weather.gladstonefamily.net/CWOP_Guide.pdf
Basically, what you're missing with your unspecified model Acurite
weather station is a radiation shield for the temperature sensor. What
you're trying to do is measure the air temperature, not the
temperature of the plastic box, the nearby walls, exhaust vents,
parking lot heat island, reflections from low-e glass, foliage
transpiration cooling, and a zillion other sources of error. Here's a
fun example:
http://802.11junk.com/jeffl/crud/KSBW-WX-Station.jpg
That's the local radio station's weather sensor array on the left,
sited over the HVAC system.
More on badly located weather stations. This site is well worth
skimming:
http://www.surfacestations.org
Even the official weather stations are often badly located:
http://www.surfacestations.org/odd_sites.htm
This is one of my early attempts at a radiation shield (pagoda):
http://802.11junk.com/jeffl/pics/wx/slides/radiation-shield-01.html
It was ok, but I missed something obvious. There's a gap near the top
of the wall where the cable goes through. Inside the building are
several high power transmitters, which produce lots of hot air, that
greatly affects the indicated temperature. Here's the CWOP report on
temperature and barometric accuracy. The station was removed and is
being moved to a better location sometime in the next month.
Enough for now. Your problem will be:
1. Do some reading on proper weather station siteing and Stevenson
Screen radiation shield construction.
2. Find a better weather station if you want accuracy.
3. Register with the various amateur weather web sites (Weather
Underground, CWOP, etc and see if your numbers track those of the
stations around you.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558