Multi-Channel and Portable Fiber Optic Combustion Pressure Sensor System

An eight-channel fiber-optic combustion pressure system is described intended for continuous monitoring and control applications in diesel- and natural gas-engines. The portable control/monitoring unit of the system offers capabilities of real-time data acquisition and triggering from a shaft position or TDC sensors. Several processing functions are offered including calculations of peak pressure (PP), Indicative Mean Pressure (IMEP), and location of peak pressure (LPP). The system allows for 50 kHz, burst mode transfer of multi-sensor data to a PC. OPTRAND's commercially available combustion sensors for 1000 and 3000 psi maximum pressure ranges can interface to the unit with optical patch cables available up to 100 meters in length. The system offers 0.1Hz to 15 kHz frequency response, 1% accuracy at constant temperature, and maximum uncooled sensor housing temperature of 300°C. Performance data are presented from seven-month endurance tests conducted at customers’ engine cites indicating excellent sensor durability and fatigue-free operation.