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.
