Subminiature accelerometers endure up to 60,000 G


Machine control
Smaller-than-dime-sized Endevco model 71 series of subminiature SMT piezoresistive accelerometers has a rugged design to measure shock.

Endevco Corp. , a Meggitt group company specializing in sensing technologies for demanding vibration, shock, and pressure applications, expanded its line of high shock sensors for the most extreme aerospace and test and measurement applications with the new subminiature model 71 series surface-mount accelerometer. The Endevco model 71 series of subminiature SMT piezoresistive accelerometers features a rugged design for shock measurements from 6,000-60,000 G and sensitivities from 3 to 30 uV/G.

The internal sensing system is micro-machined from a single piece of silicon and includes the inertial mass and strain gages arranged in an active, four-arm, Wheatstone bridge circuit complete with an innovative on-chip zero balance network. The low mass, extremely small size, and unique construction of the sensing element reportedly blends an exceptionally high resonant frequency with low output impedance, high over range, and zero damping for no phase shift.

The high resonant frequency of these sensors permits their survival in the presence of the high frequency components in a shock pulse that would shatter the seismic system of lower quality accelerometers, the company says. With resonant frequencies from 180 kHz to 700 kHz and zero damping, the 71 series responds to the fast-rise-time, short-duration shock events typical of munitions fusing, kinetic impact testing, and high shock component test applications.

With a frequency response extending down to dc, these transducers are ideal for measurement of long duration transients. They also permit integration of the acceleration data to obtain velocity and displacement measurements.

—Edited by Lisa Sutor , Control Engineering contributing editor

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