Piezoelectric pressure sensor

What is a piezoelectric pressure sensor?

In piezoelectric pressure sensors, the measuring element is based on a crystal that produces an electrical charge proportional to the pressure applied. This effect is commonly referred to as piezoelectric effect.

What are piezoelectric pressure sensors used for?

Piezoelectric pressure sensors are the first choice for the measurement of:

  • Dynamic pressures 
  • Small pressure pulsations at high static pressures 
  • Quasi-static pressure measurements in need of very small or high temperature sensors

How does a piezoelectric pressure measuring chain look like?

Piezoelectric sensors generate a tiny charge, in the order of a picocoulomb. An electronic circuit converts this into a proportional voltage signal, that can then be processed by a data acquisition system. If the electronics is an external device (charge amplifier), the piezoelectric pressure sensor is referred to as charge output or PE pressure sensor. If the electronic circuit is integrated into the sensor housing, it is referred to as a voltage output or IEPE pressure sensor (other known brand names are Piezotron, ICP, etc.).

The illustration of a piezoelectric pressure sensor shows how the pressure is transformed to a proportional electric charge.
The pressure (p) exerted by the measured fluid on the diaphragm (1) is transmitted according to the active area of the diaphragm as a proportional force to the piezoelectric crystals (2). A helical-shaped spring (3) contacts the metal coated crystal surface, which is acting as electrode, and carries the electric charge to the connector (4).