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    Decouple humidity and gas measurement BME688

    Decouple humidity and gas measurement BME688

    Christoforos
    Established Member

    Hello,

    I am new to the BME688 sensor and I need to help to decouple the humidity and gas measurement. When I espose the sensor to solvents (Acetone, IPA or ethanol) the humidity changes in the order of 3-5% that follow the gas concentration, especially with acetone. When I expose the sensor to water I get significant gas resistance variation. I attach the raw data extracted from the BSEC2 library for Arduino IDE 2.0.3. 

    How can I know if the resistance measurement is due to gas sensing and not variations in humidity and vice versa?

    Thank you!

    5 REPLIES 5

    BSTRobin
    Community Moderator
    Community Moderator

    Hi Christoforos,

    Temperature and humidity can have an impact on the gas output of BSEC. They are related, and the BSEC algorithm implements this process internally.

    Hi BSTRobin,

    Thank you for your answer. Which process does the BSEC implement internally? Do you mean that it takes the impact of temperature and humidity into account to improve the gas measurement?

    How about the BME68x library? Does the programmer have any control on the measurement? 

    Thank you!

    Regards,

    Christoforos

    Hi Christoforos,

    The BSEC algorithm internally compensates the gas output based on temperature and humidity, and the user can directly use the output of BSEC, but does not disclose the implementation details of the BSEC algorithm.

    Dear BSTRobin,

    Thanks for the answer! It makes sense! 

    Does the BME68x library (and the examples provided) give the same compensation or is it up to the user to do that?

    Many thanks!

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