First of all: compare the raw pressure readings, but therefore all sensors have to be at the same location.
The calculated "barometer" value depends on other measurements such as altitude, temperature and humidity. So, if any of the other values is off, the calculated result will be off, even when all sensors show the same absolute pressure. Guido Cioni schrieb am Sonntag, 5. Januar 2025 um 18:18:42 UTC+1: > I have 3 stations located close to each other (maximum distance is about > 12 km). > They all use the same hardware (Davis Vantage Vue). > The only difference between them is that one of the stations (which is > also the one that I'm using with WeeWx) does not have the console, so I'm > using an external BME280 sensor to get the pressure reading. > > When comparing the barometer variable (which If I understand correctly > should already be corrected with altitude and temperature) I get indeed a > similar behaviour. > [image: Screenshot 2025-01-05 at 18.11.45.png] > > However, the station with the BME280 sensor (green curve) is way off with > respect to the other ones. > Obviously, small discrepancies in the 'real' altitude could explain part > of the difference, for example the one that is seen between the blue and > red curves. However, I feel like the green line is way off possibly because > of: > - wrong calibration in the BME280 sensor > - something else going wrong when computing barometer? > > Has anyone seen this behaviour before? Should I just use an additional > line in StdCalibrate to correct the value of the pressure read from the > BME280 sensor (I could use as offset the difference with the neighboring > stations) or is there a cleaner way to correct this? > > Thanks > -- 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 [email protected]. To view this discussion visit https://groups.google.com/d/msgid/weewx-user/e9092f70-2081-4f18-91b9-20c9ae8e0a41n%40googlegroups.com.
