Measurement Uncertainty in Primary Calibration of Accelerometer Complex Sensitivity at Low Frequencies

The paper presents a case study pertaining to the analysis of factors affecting the measurement uncertainty in primary calibration of accelerometers at lower frequencies in range of 0.1 to 40 Hz using low-frequency primary vibration calibration standard realized at CSIR-National Physical Laboratory, India. The potential high accuracy and precision in measurement are achieved with a long-stroke exciter, APS 113AB having lowest transverse motion and by data acquisition at a high sampling rate and digital band pass filtering. The study evaluates the measurement uncertainty in accelerometer complex sensitivity including phase determination using a laser interferometer and an optical encoder. A comparison of the results of a laser interferometer and an optical encoder is presented. The measurement uncertainty in the sensitivity determination and phase measurements using both these approaches is validated from the results of participation in an international key comparison exercise.

Automated summary

This study evaluates the measurement uncertainty in primary calibration of accelerometers at lower frequencies using specific instruments and high sampling rate data acquisition. The sensitivity determination and phase measurements using a laser interferometer and an optical encoder are compared, with the results validated through participation in an international key comparison exercise.