What is an accelerometer?
An accelerometer is a measuring device for measuring acceleration. Both single-axis and multi-axis accelerometers measure the magnitude as well as the direction of the acceleration that occurs.
How does an accelerometer work?
Basically, an accelerometer is a force sensor on which mass is attached. The measuring signal is proportional to the occurring acceleration and follows Newton's second axiom: F=m.a. The constant mass m, also called seismic mass, evokes a force F due to the mass inertia when it is accelerated. Calibration determines the relationship between acceleration and a and force F.
Accelerometers are extremely common in dynamic testing. Microelectromechanical system (MEMS) accelerometers based on a capacitive measuring principle are used for static and low-frequency measurements. Accelerometers based on the piezoelectric measuring principle cover an enormously wide measuring range, in some cases up to more than 100'000g. The latter are available in two versions. On the one hand, there are piezoelectric accelerometers with charge output, which require a downstream charge amplifier. On the other hand, accelerometers with integrated charge amplifier electronics (IEPE) are extremely common. Typical applications of IEPE accelerometers are modal analysis of mechanical structures or measurements of NVH (Noise, Vibration, Harshness) in vehicles.