The one-time offset is a compensation for the initial installation error, and would probably be accurate for that pressure altitude only. This fixed offset is in the order of < 1hPa. The airport has a calibrated Automated Weather Observation Service, reporting the current "Altimeter Setting". This is actually the air pressure at MSL. My application has a graphic display and corresponding adjustment, and when adjusted correctly for the local altimeter setting, the altimeter reads the field elevation. The reported setting here in the US is inches of Hg, with a precision of 0.01". Each 0.01" (~0.34 hPa) is approximately 10ft in elevation at these elevations (~1000 ft). Before any drift had occurred, my altitude reading was always accurate within 10ft. Temperature wise, it is not exposed to any extremes. Outdoor temperature swings around here is between -10C through +35. Mechanically, I am actually using a breakout board since I am not confident in soldering techniques for such a small part. This is the board, that is then mounted on my main board. It would not experience any undue stress, IMO. https://www.amazon.com/HiLetgo-Precision-BMP280-3-3-Atmospheric-Pressure/dp/B01ICN5QPU After the first sensor failure, I thought I maybe had a counterfeit product. Possible?
... View more