Improved repeatability for calibration of shock accelerometers

The signal processing techniques that can then applied to the recorded waveforms to extract acceleration peak values are described. An upward-moving pneumatically-operated projectile provides a simple means for the comparison shock calibration of accelerometers. A pressure release mechanism controls the moving speed of the projectile, and the shock acceleration is created by the projectile impacting on an anvil that has pads attached to its bottom surface. A torque wrench is used to secure the mass and accelerometers to the anvil with a specified torque, and in this arrangement the top accelerometer has no mass load and the bottom accelerometer is loaded by a mass that is the sum of the cylinder mass and the mass of the top accelerometer. Replacing the 8-bit A/D converter by the 14-bit digitizer and implementing the three signal processing methods reduces the variance of the measured shock sensitivity significantly.