Piezoelectric Accelerometers from The Modal Shop, Inc.

Found naturally in quartz and synthesized in special ceramics, the piezoelectric effect is the phenomenon that an electrical charge is produced as a result to a stress applied to the material. PE accelerometers utilize this technology by mounting an inertial mass to a piezoelectric crystal. When the sensing element experiences acceleration, this inertial mass applies force to the crystal which creates stress resulting in the output of an electrical charge. Collected on an electrode, the high impedance electrical charge signal can be conditioned by either internal or external electronics for measurement purposes. Accelerometers containing internal electronics are classified as Integrated Electronic PiezoElectric (IEPE), but commonly referred to by users as “voltage mode” accelerometers. Alternatively, PE accelerometers requiring external charge amplifiers for signal conditioning are called “charge mode” accelerometers.

Voltage mode PE accelerometers incorporate built-in, signal conditioning micro-electronics. ICP®, as mentioned previously, is PCB Piezotronics’ registered trademark that stands for “Integrated Circuit Piezoelectric” and identifies IEPE accelerometers manufactured by PCB. PCB is credited as the company most responsible for development of this technology. ICP/IEPE has been adopted as the standard by the industry's sensor, analyzer and data acquisition manufacturers.