Metrological Procedure
Determination of the relationship between the physical acceleration applied to a micro-electromechanical system and its electrical output. Mems accelerometer calibration involves the systematic measurement of bias and scale factor under controlled conditions. This process uses a high-precision tilt table or a centrifuge to apply known forces.
It establishes the baseline accuracy for the device before it enters service.
Scale Factor
The slope of the output relative to the input acceleration defines the sensitivity of the unit. During mems accelerometer calibration, the system records the raw digital counts at plus and minus one gravity. This calculation produces a scale factor expressed in bits per unit of acceleration.
Thermal Compensation
Variation in the environment causes the bias of the sensor to shift over time. Performing mems accelerometer calibration across a wide temperature range allows the creation of a lookup table. The firmware uses this table to subtract the predicted offset based on the current temperature reading.
Stability Verification
Long term performance depends on the aging characteristics of the mechanical structure. A final mems accelerometer calibration check occurs after the device has undergone environmental stress testing. This step ensures that the soldering and packaging stresses have settled into a permanent state.
