Calibration of vibration pick-ups with laser interferometry: part IV. Development of a shock acceleration exciter and calibration system

Abstract

Measuring shock acceleration with peak accelerations ranging from 200 to 5000 m s−2 is a significant concern for mechanical or electrical applications in industries. To precisely calibrate accelerometers using shock acceleration, we developed a shock acceleration calibration system at the National Metrology Institute of Japan. In the calibration system, the shock acceleration exciter generates shock acceleration using rigid-body collisions between three metallic bars inside an air bearing. The pick-up to be calibrated is fixed on an edge surface of the third metallic bar so that the pick-up moves together with the metallic bar. The displacement of the pick-up is measured by a He–Ne laser interferometer with traceable voltage, length and time standards. The sensitivity of the pick-up is evaluated by analysing signals from the accelerometer and laser interferometer. We describe the calibration procedure, the specification of the shock acceleration calibration system and the uncertainty in the shock-acceleration calibration. The shock acceleration calibration result has the expanded uncertainty of roughly 1.0% with a coverage factor 2 and is comparable to the vibration acceleration calibration result with an En value below 0.3.