3. Accelerometer Designs

The basic function, i.e. the conversion of mechanical acceleration into an electric signal, is identical for all kinds of piezoelectric accelerometers. The reason for using different piezoelectric systems is their individual suitability for various measurement tasks and their varying sensitivity to environmental influences.

We use three different mechanisms for the mechanical-to-electrical conversion. Our type codes “KS”, “KD” and “KB” are derived from these designs.

Shear system (“KS”)

Compression system (“KD”)

Bending system (“KB”)

The following table summarizes the advantages and disadvantages of these three designs:

Shearing
“KS…”		Compressing
“KD…”		Bending
“KB…”
AddvantagesLow temperature transient sensitivity
Low base strain sensitivity		High sensitivity-to-mass ratio
Robustness
Technological advantages
Cost efficient manufacturing		Best sensitivity-to-mass ratio
DisadvantagesLower sensitivity-to-mass ratioHigh temperature transient sensitivity
High base strain sensitivity		Fragile
Relatively high temperature transient sensitivity

Shear design is applied in the major part of modern accelerometers due to its better performance.

The following illustrations show the three designs in existing accelerometers.