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    pressure sensors absolute vs relative accuracy

    pressure sensors absolute vs relative accuracy

    New Poster


    How does the absolute vs relative accuracy relate for longer term barometric pressure measurements.

    To be more specific :

    If the sensor is placed in the same place for a longer period how would the accuracy evolve after a precise calibration (with 0.1 hPa accuracy) at that location.  I was thinking 3 months to a year.

    (10-30°C ambient temperature, coud be heated  above 25°C in enclosure)

    BMP390L :

    absolute accuracy :   0.4 hPa  (temperature 25..40 °C)

    relative accuracy : 0.03hPa (temperature 25..40 °C)

    long term stability : 0,16 hPa


    BME680 :

    absolute accuracy :   0.6 hPa  (temperature 0..65 °C)

    relative accuracy : 0.12hPa (temperature 25..40 °C, but constant humidity?)

    long term stability : 1.0  hPa










    3 REPLIES 3

    Community Moderator
    Community Moderator


    Before the long term test, you need confirm the enviroment pressure and temperature is fixed.  Most factor will impact the enviroment pressure, examples wind/weather/temperature. So, please exclude these influence.

    If you want to check sensor's long term stability, maybe put pressure sensor in chamber and confirm the temperature and pressure fixed. Meanwhie, please refer to BMP390L datasheet , Long term stability.

    Best regrads.



    For me a long term test would be a "live" situation (I would use a indoor location with 20-25°C).  It's rather easy to calibrate to a meteo station in the -close- neighbourhood and to test it against that same meteo station later, if the wind speed is very low.


    The big question is if I can start with the relative accuracy (at the time of calibration) and use only the long term stability to calculate the error for the next year.  In that case the BMP390L would be very accurate.

    Community Moderator
    Community Moderator


    BMP390L as latest pressure sensor, have best performance. While, it's better make periodic calibration to keep pressure sensor with better accuaracy.

    Best regrads.