Testing Techniques Involved with the Development of High Shock Acceleration Sensors

This paper describes testing techniques and equipment used in the development of the Endevco Model 7270 Shock Accelerometer, having a range beyond 100,000 g and a mounted resonant frequency on the order of a megahertz. Conventional testing techniques proved inadequate for thorough evaluation. A new calibration system based on the Hopkinson bar has been developed to give rigorous and accurate tests to determine sensitivity, amplitude linearity and zero shift due to accelerations beyond the transducer's designed full scale acceleration level. A related but smaller apparatus was developed to determine resonant frequency and also, although to a very rough degree, the frequency response of the accelerometer. It provided the means to create sub-microsecond rise time strain waves to excite an accelerometer's resonant frequency.