The active element of an accelerometer is a piezoelectric material. Figure 1 illustrates the piezoelectric effect with the help of a compression disk. A compression disk looks like a capacitor with the piezoceramic material sandwiched between two electrodes. A force applied perpendicular to the disk causes a charge production and a voltage at the electrodes.

For decades the applications of sensors measuring torque and force changed rather little. In recent years new challenges arose which require new innovative solutions for sensors and large volumes in sensor production. Conventional torque sensors on the basis of strain gauges are still very useful for very precise measurements in test applications, for instance. However, they are very expensive and also their maintenance is very costly. This prevents their use in large numbers and they are therefore not suitable for...

Under normal conditions, piezoelectric sensors are extremely stable and their calibrated performance characteristics do not change over time. However, often sensors are exposed to harsh environmental conditions, like mechanical shock, temperature changes, humidity etc. Therefore it is recommended to establish a recalibration cycle. For applications where high accuracy is required, we recommend to recalibrate the accelerometer every time after use under severe conditions or at least every 2 years. In some less critical applications, for example in machine monitoring, recalibration...