As far as I can tell the anemometer should be at 10m (33ft), temperature at about 6ft and rain gauge no higher than 6 ft - so how you do that with an all-in-one I do not know!!!!
It is possible from your photograph that both the tree behind and the fence could be having an impact on your readings - hard to tell!! On Wednesday, 25 January 2017 13:59:15 UTC+2, Michael Connors wrote: > Andrew, > > That is possible of course but I don't really think so. My sensors are > mounted over grass on a wooden fence at an elevation of 7' AGL and sees > afternoon shade during the summer. But it heats up pretty fast as soon as > the sun comes up and the temperature stays elevated until it's in the > shade. I'm at an elevation of 1589 meters so there isn't too much > convection cooling by the surrounding air compared to a station at a much > lower elevation. The inboard aspiration fan is working in sunlight. Take a > look at the installation and tell me what you think. Temperatures now > during the winter seem more reasonable and match the neighboring > wx-stations. I had it mounted at 10' above the roof and that was even > worse because of the radiated heat from the flat roof. It got much better > when I moved it to the current location. > > There is a picture of the installation here at: > http://weather.gladstonefamily.net/site/AV175 > > Thanks, > > Mike > > > On Tuesday, January 24, 2017 at 9:15:52 PM UTC-7, Andrew Milner wrote: >> >> Could the differences you 'observe' be caused by physical factors such as >> mounting position above the ground, terrain around sensor, one station in >> shade one exposed to sun, not all fan aspirated etc etc?? a strong sun can >> really heat up some kinds of soil and vegetation which is then radiated and >> reflected around - unless you are all using the same Stephenson screens at >> the same height above ground. >> >> >> On Wednesday, 25 January 2017 05:12:26 UTC+2, Michael Connors wrote: >> >>> I am curious whether one of the programmers of the weewx driver or >>> application for the Acurite 2036C could add a means to offset the >>> temperature by different values between >>> sunrise and sunset, and sunset and sunrise. The current configuration >>> file (see below) allows the use of a formula to change the readings but it >>> is not time specific. (see below) >>> >>> The Acurite 5-in-1 temperature accuracy is poor during the summer, due >>> to the intense summer sun heating of the instrument body causing the >>> temperature to read higher than the actual >>> temperature really is even when the fan is running. The reading can >>> read as much as 4° to 5° higher than the actual temperature from my >>> experience. This is comparing my temperature readings to nearby >>> CWOP weather stations within a couple miles. >>> >>> >>> ######################################################################## >>> # This section can adjust data using calibration expressions. >>> >>> [StdCalibrate] >>> >>> [[Corrections]] # For each type, an arbitrary calibration >>> expression can be given. >>> # It should be in the units defined in the StdConvert section. >>> # Example: >>> #foo = foo + 0.2 >>> >>> pressure = pressure - 0.038388984 # -0.9 hPa >>> >>> >>> ########################################################################## >>> >>> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
