Railed Piezo Electric Accelerometer: Understanding Its Limitations

Piezoelectric sensors are widely used to measure physical inputs such as vibrations, shocks, and other mechanical disturbances. One type of piezoelectric sensor is the piezo electric accelerometer, which offers a wide temperature range, broad dynamic range, and wide bandwidth (up to 10 kHz). Despite these benefits, railed piezo electric accelerometers have some limitations that engineers should be aware of.

In real-world applications, physical inputs rarely resemble half-sine impulses. However, when tracking slow motion with an AC-coupled device, the problem remains the same. DC-response devices can accurately follow slow-moving inputs without issue. However, AC-coupled devices may struggle to track such inputs due to their intrinsic limitations.

For instance, consider using an AC-response accelerometer to measure a long-duration half-sine input pulse. At the end of the half-sine pulse, the output of the AC-coupled device will produce an undershoot (offset) due to its RC time constant. This limitation can result in significant errors during numerical integration.

To illustrate this problem further, imagine integrating and double-integrating the signal from an accelerometer to derive velocity and displacement. The g-value may provide a good reference, but engineers often need velocity and displacement data for design calculations. In most vibration studies, acceleration, velocity, and displacement are essential variables that must be accurately measured.

In conclusion, while railed piezo electric accelerometers offer many benefits, they also have limitations that must be considered. Engineers should be aware of these limitations when designing or validating structures to ensure accurate measurements and reliable results.

Railed piezo electric accelerometer