Tiny piezoelectric accelerometer
Meggitt Sensing Systems, a Meggitt group division, introduced the Endevco model 25A, the world’s smallest Isotron (IEPE-type) piezoelectric accelerometer, designed to support high-reliability vibration measurement requirements on very small structures and objects. With a total weight of just 0.2 gram, its lightweight design effectively reduces unwanted mass loading effects.
Featuring a durable shear mode construction, the Endevco model 25A reportedly incorporates integral electronics which convert high-impedance input into a low-impedance voltage output through the same cable that supplies the required 4 mA constant current power. Signal ground is isolated from the unit’s mounting surface by a hard anodized surface. The unit comes with two pre-installed, easily field-reparable fine gage (34 AWG) wire output leads, allowing for immediate field use. If required, a new assembly lead may also be reinstalled at the factory. A heavier gage (28 AWG) cable is also provided for extension purposes. In addition, an optional triaxial mounting block (model 2950M16) is available to facilitate three-axis vibration measurement requirements. Units are adhesive mounted with a special field removal tool (model 31275) supplied for convenience.
With its small size and exceptional performance attributes, the Endevco model 25A is well-suited for measuring overall vibration levels of scaled models and smaller electronic components within aerospace, automotive, electronic products, and in-laboratory testing applications, as well as biomedical research. Recommended optional accessories, sold separately, include the model 133 three-channel piezoelectric signal conditioner; the model 4416B low-noise, compact signal conditioner; the model 2775B PE, Isotron and RCC signal conditioner; the model 6634C vibration amplifier; the model 4999 multi-channel signal conditioner; or the Oasis 2000 (4990A-X with cards 428 and/or 433) computer controlled system.