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    BMEX80 humidity measurement

    BMEX80 humidity measurement

    JCD
    New Poster

    How does the BME280 technically measure humidity?

    Background: We have put the sensor into a hermetically sealed Al-Cu-B housing filled with a mixture of argon and CO2. Since several days the humidity reading constantly increases to now 2.5 % (after 6 days). We do not expect any significant quantity of humidity inside as it was evacuated for at least 12 hours before filling. However it could be, that some of the components inside the box are outgassing, therefore the question is to which chemical substances the BME280 could also be sensitive to which fake a humidity signal? 

    1 REPLY 1

    handytech
    Community Moderator
    Community Moderator

    The BME280 measures humidity by the relative permittivity change of a polymer-based capacitor.

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