Dynamic Calibration Uncertainty of Three-Axis Low Frequency Accelerometers

In this paper a methodology concerning the static and dynamic calibration of three-axis low-cost accelerometers in the (0 to 10) Hz frequency range is described, to be used for evaluation of existing civil infrastructures. Main and cross sensitivities of the accelerometers have been experimentally estimated by means of the matrix sensitivity concept. The standard deviation of accelerations obtained along all three axes using different calibration data sets in repeatability conditions has been calculated and intended as dynamic calibration uncertainty. The method has been validated by using reference accelerations accurately realized, in order to evaluate the residual bias error. Static and dynamic calibration test benches have been used to realize reference accelerations. In order to create a three-axis acceleration field, a mechanical arm is used in static calibration; a rotary device is used in order to test the accelerometers in dynamic conditions. According to the procedure described in this paper, a great improvement of the low cost accelerometers’ metrological characterization could be achieved, especially in dynamic working conditions.