Frequency analysis
Shock metrology
Piezoelectric transducers
Signal conditioning

Piezo transducers

Piezoelectric accelerometer

Dynamic range: 108 : 1 (160 dB)


  • Wide frequency range
  • Compact, often low weight
  • High stability
  • Can be mounted with any orientation
  • Self generating High impedance output
  • No moving parts, no wear No true DC response
  • Rugged
  • Very large dynamic range


  • High impedance output
  • No true DC response

    Piezoelectric materials

    When a force is applied to a piezoelectric material in the direction of its polarization an electric charge is developed between its surfaces, giving rise to a potential difference on the output terminals. The charge (and voltage) is proportional to the force applied. The same phenomenon will occur if the force is applied to the material in the shear mode. Both modes are used in practical accelerometer design.

    Compression type design

    This traditional, simple construction gives a moderately high sensitivity-tomass ratio. In the Centre-mounted configuration shown, the piezoelectric element-spring-mass system is mounted by means of a cylindrical centre post attached to the base of the accelerometer.

    The design is very stable, but even with careful design the influence from environmental parameters is higher than for the other construction types.

    Therefore this design is especially used for accelerometers which are intended for measurement of very high shock levels and special purpose accelerometers.

    Shear type design

    Shear type accelerometers have the advantage that they intrinsically are rather insensitive to environmental parameters like temperature transients and base strain. A high sensitivity-to-mass ratio can be obtained, and this helps to create miniature accelerometers as well as high performance general purpose accelerometers. The piezoelectric elements are arranged in such a way that they are subjected to shear forces from the seismic mass when accelerated.

    Choosing an accelerometer

    The range of operation is the first to be considered when selecting an accelerometer.

  • General Purpose Type Accelerometers
  • Small (miniature) Accelerometers

    Accelerometer Calibration

    Setups similar to the setup shown above are used to calibrate accelerometers with very high accuracy (1%) at a reference frequency (normally 160 or 80 Hz) and also over wider frequency ranges with slightly less accuracy. This method, using a Reference Standard Accelerometer in a so called Back-to-back configuration or in a fixture, is widely