Integrated circuit piezoelectric sensor

An integrated circuit piezoelectric sensor or ICP sensor is a device used to measure dynamic pressure, force, strain, or acceleration. It contains a sensing element made of a piezoelectric material, which converts mechanical strain into an electrical signal, and an electronic circuit to amplify this signal and transmit it to an external device.

ICP is an abbreviation of "integrated circuit piezoelectric", and is a registered trademark (no. 1,603,466 in the USA) of PCB Group, Inc., parent company of PCB Piezotronics.^[1] There is a similar non-proprietary standard called IEPE, which stands for "integrated electronics piezoelectric."^[2]

In an ICP sensor, the built-in electronics convert the high-impedance charge signal that is generated by the piezoelectric sensing element into a usable low-impedance voltage signal that can be readily transmitted, over ordinary two-wire or coaxial cables, to any voltage readout or recording device. The low-impedance signal can be transmitted through long cables and used in dirty field or factory environments with little degradation. In addition to providing crucial impedance conversion, ICP sensor circuitry can also include other signal conditioning features, such as gain, filtering, and self-test features. The simplicity of use, high accuracy, broad frequency range, and low cost of ICP accelerometers make them suitable for use in most vibration or shock applications. They cannot, however, be used where the ambient temperature exceeds the capability of the built-in circuitry. The routine maximum temperature of ICP accelerometers is +250 °F (+121 °C); specialty units are available that operate to +350 °F (+177 °C).

The electronics within ICP accelerometers require excitation power from a constant-current regulated, DC voltage source. This power source is sometimes built into vibration meters, FFT analyzers, and vibration data collectors. A separate signal conditioner is required when none is built into the readout. In addition to providing the required excitation, power supplies may also incorporate additional signal conditioning, such as gain, filtering, buffering, and overload indication.

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