1. Different types of measurement

Micro-accelerometers generally use mechanical structures with a "seismic mass" (name given to the heavy part that will be sensitive to acceleration: figure 1 ). This is called a "static" structure. A second principle is to use a resonant mechanism consisting of a mass/spring system. The device's resonant frequency changes with the acceleration applied. This is referred to as a "dynamic" or "resonant" structure (see figure 3 ).