MEMS Accelerometers can be supplied as either unamplified, which give a raw bridge output, or amplified. Unamplified MEMS accelerometers tend to use piezoresistive technology to produce an output proportional to the acceleration event. A piezoresistive accelerometer use a cantilever beam with a tip mass to react to accelerations. A set of piezoresistive strain gauges fixed to the beam change their resistance as they undergo tension and compression. This signal is fed into a Wheatstone Bridge, where temperature compensation is often carried out.
Through the use of overtravel stops and damping, using both liquid and gas medium, the accelerometers are able to withstand high levels of shock. This, along with the high bandwidth of the sensors makes them ideal for measurements of sock event. For this reason, they’re often used in crash testing ATDs and sleds and weapons tests.
