Prepolarized microphones were designed a few decades after their counterpart the traditional externally polarized microphones were developed. Prepolarized microphones have many advantages over the externally polarized models. This design utilizes power circuitry that PCB® invented for sensors, called ICP® power. By applying a polymer coating to the top of the backplane and embedding a charge on it, you can now eliminate costly 200V power supplies and use an 2-20 mA constant current supply or signal conditioner as a power source.

Prepolarized models are better suited for portable applications or ones that may see high humidity. An added benefit is their interchangeability with other NVH test equipment, for example most accelerometers or piezoelectric pressure sensors. This allows the use of low cost coaxial cables with 10-32, SMB or BNC connectors. With a multiple channel power supply, you can perform your vibration and acoustic tests within the same set-up, saving both time and money.