Fast-response piezoresistive pressure transducers for thermofluids experiments

Thermofluids experiments often require the use of fast-response pressure transducers\nthat maintain their accuracy over a wide range of operating temperatures. Existing\npressure sensing technologies are available which suit these demanding applications,\nhowever these transducers are usually relatively expensive. This project investigates the\nuse of inexpensive piezoresistive pressure transducers in the measurement of transient\nfluid pressures.\nA temperature compensation routine was developed which improved the accuracy of\nthe piezoresistive pressure transducers over a substantial range of operating temperatures. A \n\ndynamic response analysis indicated that the diaphragm resonant frequency\nof these sensors was 246.7 kHz (without the addition of latex or grease) and that the\nresponse times could be improved from approximately 12.5 'ms' to 0.38 'ms' with simple\ncase modifications. These results demonstrated the suitability of piezoresistive pressure\ntransducers for use in fast-response thermofluids experiments.\nA piezoresistive pressure transducer produced very similar results to a piezoelectric\nsensor when both devices were tested simultaneously in the USQ Gun Tunnel. This\nindicated that the piezoresistive sensor was capable of accurately recording rapid fluctuations in \n\npressure levels. The cylinder pressures of an internal combustion engine\nrecorded by a piezoresistive and piezoelectric sensor also compared well. The high\noperational temperatures of the engine verified the success of the piezoresistive sensor\ntemperature compensation routine.