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    BME280 Humidity Reading Discrepancy

    BME280 Humidity Reading Discrepancy

    New Poster

    I have a pair of BME280's on Adafruit breakout boards, running side by side in open air reading ~10%RH apart.

    Is this issue likely to be fixable by going through the reconditioning procedure or is the discrepancy too large and indicative of damage?

    Both sensors are set to the same filtering/averaging, and are read out via an Arduino.
    Both sensors have had pins soldered to their breakout board adhering to the soldering instructions, then left for 5+ days at 25C/40%RH to settle.
    The sensors are from different lot numbers (736 and 672)


    7 REPLIES 7

    A large delta in humidity reading (usually negative) often indicates a problem with the manufacturing, where the sensor was damaged due to washing, chemicals or other manufacturing processes.

    As a first step, I would review the Handling and Soldering Instructions with the manufacturing process used.

    I have the same problem.
    I have two BME280 sensors soldered on the little PCBs, which i bought on Aliexpress.
    Both of them are accurate in temperature and pressure, but show different RH compared to each other and compared to the calibrated Honeywell's HIH4000 analog RH sensor.
    One have a constant offset about 20% and another 7% relatively to HIH4000 measurements.
    Is it possible that the producer of the PCBs damaged sensors during reflow? Can reconditioning procedure restore the calibration of the sensors?

    If both parts report low humidity with correct temperature, that is *usually* a telltale sign of manufacturing issue...

    Since you did not make the boards, it would be hard to debug further.

    BME280 sensors both report higher humidity than two reference HIH4000 sensors, which are precisely calibrated according to their passports. One BME280 have +7% and another have +20% positive offset of relative humidity.
    The offsets for both BME280 almost constant in the range between 12%RH to 35%RH.
    Сan i hope that these positive offsets can be eliminated after reconditioning procedure?
    And is it possible at all to solder new sensors without the need of reconditioning their calibration?