BME280

[jkendall]

Regarding the BME280 Combined humidity and pressure sensor. I have a few questions:

1. Is it lifetime calibrated?
2. How many years is calibration guaranteed?
3. Can anyone provide me with certificates of the above?

[handytech]

The BME280 is calibrated once during production and the resulting coefficients are stored in a Non-Volatile Memory (NVM) of the sensor.

It is mandatory to use these coefficients and the associated compensation formulas, as described in the datasheet and implemented in the recommended sensor API. The available sensor's specifications are also provided in the product's datasheet.

[jkendall]

Thanks for getting back to me.

We have successfully implemented the compensation fomulas.

Do the sensors ever require recalibration, after production?
What is the expected lifetime for a sensor to remain calibrated?
Do Bosch provide certification on the expected lifetime of calibration?

[handytech]

The "built-in" compensation is a one-time process done during the production of the sensor and any further calibration would have to be done externally. Therefore no extra certification is available, other than the specifications included in the sensor's datasheet.

[jkendall]

Is it possible for the sensor itself to give inaccurate readings after time? Or would it fail completely?

What are the estimates for the working lifetime of a sensor?

Are these estimates guaranteed or certified at all?