BME280 humidity offset

[buja]

Dear Team,

We are using BME280 to monitor humidity and temperature. Temperature is working as expected but humidity has got an offset always.

We have bought a couple of humidity sensors, which will be the reference humidity value. You can see from the above graph that all the BME280s (green lines) are having a negative offset on the humidity value (RED is the reference). We are using the APIs from the Bosch sensortec github. Why do you think there is an offset ?

The datasheet says the reconditioning procedure is mandatory after soldering process. We haven't done the reconditioning. Could that be the reason for the offset ? Also, could you please suggest us the best way to do the reconditioning ? Are there any standard device which can do the reconditioning in the production ? 

[BSTRobin]

Hi buja,

Normally, such kind of test need to be donw in a standard laboratory.

[buja]

do you suggest any equipment where we can control the humidity for testing ?

[BSTRobin]

Hi buja,

Our equipment is GPR-2 manufactured by ESPEC test equipment.