Hi SIr: Regarding BME680 calibration and verification description in our lab, please see the datasheet 1.2 Gas sensor specification. We use bvoc mixture to test sensor and besc algorithm and create baseline, but base line need be re-created with the environment change. So when the customers use a new BMP680, need to run under a good environment and a bad environment to re-create baseline until accuracy is 3. The IAQ accuracy is reflects the current state of the background calibration process, such as: IAQ Accuracy=0 could either mean: BSEC was just started, and the sensor is stabilizing (this lasts normally 5min in LP mode or 20min in ULP mode), there was a timing violation (i.e. BSEC was called too early or too late), which should be indicated by a warning/error flag by BSEC, IAQ Accuracy=1 means the background history of BSEC is uncertain. This typically means the gas sensor data was too stable for BSEC to clearly define its references, IAQ Accuracy=2 means BSEC found a new calibration data and is currently calibrating, IAQ Accuracy=3 means BSEC calibrated successfully.
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