Working lifetime of a sensor is highly dependant on the use-case, environmental and stress conditions, etc. Therefore we cannot guarantee a standard lifetime because there are so many differents applications and respective mission profiles our sensors are used for.
We do not have extra calibration certificates for our sensors, as the expected performance is already as listed in the specifications of the datasheet.
Bosch Sensortec manufactures MEMS sensors for the consumer electronics industry. As such, our parts do not have a guaranteed lifetime
Every part is however designed and expected to keep working and be acurate for over 10 years, while staying within the specifications of the datasheet.
If your application requires a higher level qualification, then I can recommend that you take a look at the Bosch Semiconductors lineup of products.
This support forum is only for Bosch Sensortec products, such as the BME280