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    BMP390 water level measurement

    BMP390 water level measurement

    New Poster


    I am using two BMP390 sensors (adafruit breakout board) to measure relative altitude (vertical distance between the two sensors).

    I have setup both sensors to the values recommended in the data sheet for highest resolution and low noise:

    • Highest pressure oversampling: x32
    • Recommended temperature oversampling: x2
    • Highest IIR filter coefficient: x128 


    With this settings, I take forced measurements every second from both sensors at floor level of the same room. 

    The pressure difference is close to zero (some calibration may be required) but I am also observing tha the difference fluctuates in a range 5Pa wide.
    Is that what I should expect given the accuracy specs of the sensor?

    If that is the case, how can this sensor track the water level of a washing machine with mm precission? As the Bosh video (84) Water level detection in washing machines enabled by BMP390 - YouTube seems to suggest


    7 REPLIES 7

    Hi Robin,

    I understand that +/-25cm (not meters) is the accuracy of air pressure equivalent altitude. And that is precisely what I was trying to measure but as I described in my previous post, I am getting a much larger range over a 5 minutes period (around 70cm).
    How can the sensor be used as an altimeter in a drone then?

    Regarding your description of the water level measurement, it suggests that the sensor is measuring hydrostatic pressure. Can this sensor be mounted underwater?  

    Community Moderator
    Community Moderator

    Hi BorisVian,

    Normally, the test needs to be tested in a standard Lab environment. What is your test environment like?

    Community Moderator
    Community Moderator

    Since there was no feedback for a long time, we close this topic first. You could update feedback in the future if you have.