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A new method is described to provide a primary calibration of shock measurementsproduced by a shock measurement system consisting of pendulum excitation and laserDoppler velocimetry. The method uses the laser Doppler velocimeter to determine thetotal distance traveled by a rigid block that slides along a Teflon (fluorocarbon)channel after being struck by a pendulum head, and the resulting distance is compared tothe distance measured by an SI-traceable length measurement. The instantaneous velocityof the block is measured by the velocimeter and is used to calculate the displacement ofthe block by integrating the velocity data. The result is compared to the displacementmeasured using calibrated rulers and calipers. The method was applied to anindependently calibrated commercial velocimeter for impact accelerations ranging from2000 to 30,000 m/s2. The results of the independent mechanical-displacement measurementsagreed with those from the commercial velocimeter to within ±0.3 %, with betteragreement above accelerations of order 10,000 m/s2 to within ±0.1 %. A conservative,upper-bound, uncertainty analysis included the effects of noise and other random errors,as well as type B estimates for systematic errors from occasional momentary demodulationfailures (dropouts), use of a different number of rulers before and after shock distancemeasurement, and the relative frequency response of the velocimeter.

Shock Measurements Based on Pendulum Excitation and Laser Doppler Velocimetry: Primary Calibration by SI-Traceable Distance Measurements