Inertial accelerometers

Inertial accelerometers, whose operating principle uses the inertial property of matter, are designed to measure the quantity : $\overrightarrow{A}\stackrel{\text{Δ}}{=}\overrightarrow{{\gamma }_a}-\overrightarrow{\phi }$ to which their casing is subjected,

with ${\overrightarrow{\gamma }}_a$ absolute acceleration,

$\overrightarrow{\phi }$ local gravitational field,

$\stackrel{\text{Δ}}{=}$ equal to by definition.

The magnitude $\overrightarrow{A}$ is therefore not generally equal to an acceleration, this word having the meaning attributed to it in kinematics, i.e. the second derivative of a position, relative to a well-defined reference trihedron. For this reason, $\overrightarrow{A}$ can be called :

• accelerometric reading (or measurement) ;

• non-gravitational acceleration ;

• non-gravitational mass effort.

On the other hand, the term acceleration should be avoided, as it can lead to confusion with ${\overrightarrow{\gamma }}_a$ .

These devices are mainly used for inertial navigation, vehicle piloting and vibration measurement.

The market is divided into two categories:

• precise and relatively expensive non-vibrating accelerometers;

• vibrating accelerometers.

After examining the theory and principles behind these devices, we present...