BME280- Humidity reading lower than expected

[TronOz]

Hi forum,

We are using the BME280 sensor in our product. What we have seen is, in newer batches of BME280, the Humidity value being read from the sensor is lower. This, we are comparing with our golden batch( reads the right Humidity value). The difference between the 2 batches has been about 2 years. The Manufacturing process has been similar. We have tried the reconditioning process but the issue remains. We were wondering if somebody has experienced similar problem and could point us in the right direction. We are using the Bosch API.  Thanks in advance.

[BSTRobin]

Hello TronOz,

Some questions to you:
1.New BME280 part read lower humidity value, old BME280 part from two years ago read right humidity value, is it correct?
2.In what environment do you test the humidity?
3.Was it tested in the same environment? If yes, what is the specific data difference?

[TronOz]

Hi,

Thanks for your reply.

Answering your questions:

1.New BME280 part read lower humidity value, old BME280 part from two years ago read right humidity value, is it correct? Yes, this is correct.
2.In what environment do you test the humidity? We test in a normal room environment, with both new and old sensors in devices, at same height and not too far from each other.
3.Was it tested in the same environment? If yes, what is the specific data difference? The new ones are reading 10% lower.

We have tried, getting the boards manufactured from different manufacturers and we see same difference from the golden sample. We hope, there was no major change from Bosch which could have caused the difference ? As I have mentioned before, we are using the BOSCH API.

Thanks.

[BSTRobin]

Hello TronOz,

Thanks for your feedback.

Could you introduce your end products in detail? Is there a heat source in the equipment?

For the old and new BME280, could you provide log data when they tested in same environment?