High G shock accelerometers

Meggitt Sensing Systems has announced the launch of Endevco® model 7255A, a miniature, lightweight piezoelectric accelerometer with integral electronics. The rugged design and performance characteristics of this model make it ideal for use in near-field, high shock and high-level mechanical impact testing applications, where unwanted high frequency signals often mask critical low-level, low frequency data.

Endevco® model 7255A incorporates a built-in mechanical filter, which blocks high-frequency energy associated with near-field high shock, and protects the sensing element from overstress. An internal electronic filter prevents saturation. The sensor features a two-wire system with integrated hybrid signal conditioner, which transmits a low-impedance voltage output through the same cable that supplies required constant current power. Signal ground is connected to the inner case of the unit, acting as a shield. Both output and signal ground terminals are electrically isolated from the mounting surface. For lower level shock measurements, a high output version is available. Both versions include internal sensor assembly strain isolation, which reduces strain input due to bending motion on the mounting surface, often found in high shock events.

Included with Endevco® model 7255A are two small gauge, lightweight hook-up wires, for use with the two solder-pin terminal interface. The wire configuration is well-suited for this type of shock sensor, as wires do not exhibit the triboelectric effect under motion, a benefit which facilitates device mounting with minimal strain to both device and cable. The resultant strain minimization significantly reduces potential for zero shift, and ensures high-reliability and performance.