Measurement error after high humidity in BME 280

[metinsariaslan]

We were using our BME280 board in our cooling chambers, where the conditions are 100% humidity and 0 degrees Celsius. We control the chamber's air conditions using various devices and chose the BME280 to measure the temperature, humidity, and pressure of the chamber. Additionally, we occasionally heat the chamber from 0 degrees to 20 degrees Celsius. After some usage, we encountered a temperature measurement error: it constantly measures -40 degrees Celsius. What might be the problem? According to the information on your page, this device should be able to operate under 100% humidity. What could be the issue?

[BSTRobin]

Hi metinsariaslan,

Thanks for your inquiry.
We usually do not recommend using the sensor in extreme environments for a long time, as this can affect the stability of the sensor.
BME280 data sheet contains our recommended humidity range for use:

When you get temperature of -40 degrees Celsius, does the temperature remain at -40 degrees Celsius? If you place the sensor at room temperature, can it resume normal temperature measurement?
Additionally, if user test at 100%rH environment, condensate water will be continuous on the sensor surface which over the dew point. If the water drop continuous on the MEMS surface, will have influence/damage with the sensor. You can Integrate with waterproof film which can protect the sensor.

[metinsariaslan]

Hi BSTRobin

Thanks for your reply as you said  the environment is extreme but after cleaning and executing the sensor at room temparature it still gives me the same result . I am also measuring the other components of the board except bme280 chip ı dont see any unexpected outputs but you might be right on this statement "If the water drop continuous on the MEMS surface, will have influence/damage with the sensor. "