AN4399HighPrecisionCalibrationofaThree-Axis.PDFVIP

Freescale Semiconductor Document Number: AN4399 Application Note Rev. 2.0, 10/2015 High-Precision Calibration of a Three-Axis Accelerometer by Mark Pedley 1 Introduction Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Three-axis accelerometers supplied for the consumer 1.1 Key words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 market are typically calibrated by the sensor 1.2 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Absolute or Relative Calibration . . . . . . . . . . . . . . . . . . . 3 manufacturer using a six-element linear model 3 Original Factory Six Parameter Calibration . . . . . . . . . . . 4 comprising a gain and offset in each of the three axes. 4 Final Product Six Parameter Calibration . . . . . . . . . . . . . 6 5 Optimal Measurement Orientations. . . . . . . . . . . . . . . . 11 This factory calibration will change slightly as a result of 5.1 Two measurement orientations . . . . . . . . . . . . . . . 12 the thermal stresses during soldering of the 5.2 Three measurement orientations. . . . . . . . . . . . . . 14 accelerometer to the circuit board. Additional small 5.3 Four measurement orientations. . . . .