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    BME 680 low humidity values

    BME 680 low humidity values

    MassaRoddel
    Member

    I am getting very low humidity values from the sensor. I use the source code from github to control the sensor and do the calculations. Pressure and temperature values seem to be ok.

    Here is an example:

    pressure: 998,7mbar

    temperature: 41.88C (the pcb is warm)

    humidity: 14.88%

    What could be the problem?

    4 REPLIES 4

    FAE_CA1
    Community Moderator
    Community Moderator

    Hi,

    Thanks for your inquiry.

    Please get a humidity meter as a reference to check the humidity value that you got from BME680.

    Thanks.

    Humidity is about 51%.

    I attached the self test results. Test was made about 30 minutes after system was running.

    Also, I wonder why we get gas resistance up to 6MOhm. According to the documentation I would expect much less. We have two prototypes which show the same results. Communication is SPI @4MHz.

    Alain1
    New Poster

    Given the "high" temperature I wouldn't be suprised that the RH is really that low at 42°C.

    The RH does change a lot depending on the temperature and the 42°C is used to calculate it.

     

    If you need the RH, I expect that it's needed to lower the PCB temperature quite a lot and then do a recalculation to the room temperature.

    Thank you, that makes sense. If the gas resistance values are also ok then everything is fine. I was worried that we might have broken the sensors during soldering. Our application is not about air quality.

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