The 350500 Dynamic Pressure Charge Amplifier (DPCA) is a component in a dynamic pressure sensing system. This sensing system, which monitors pressure pulsations that result from combustion instability in gas turbine engines, consists of a charge-coupled piezoelectric pressure sensor, low noise interconnect cable, 350500 charge amplifier, and monitoring device.
The dynamic pressure sensor should be a high temperature piezoelectric type that converts dynamic pressure to an output signal scaled in pico-coulombs per unit of pressure. The 350500 charge amplifier design allows its use with a number of sensors designed to monitor combustion instability.
The interconnect cable, which connects the sensor with the charge amplifier, is a specially designed low-noise, environmentally robust cable. The 350500 DPCA offers two interconnect cable options. The 350500 charge amplifier converts the sensor charge signal to a low impedance voltage output signal. This signal is suitable for Bently Nevada monitors such as the 3500/64 Dynamic Pressure Monitor. The electrical interface from the monitor to the charge amplifier, which consists of –24 Vdc power, common, and signal, is the same as that for a Bently Nevada Proximitor. Appropriate safety barriers can be used between the charge amplifier and the monitoring device.