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Micromachined resonant pressure sensors are the optimum selection of pressure monitoring in aerospace,industrial process controlling and other precision measurement fields,because of their high accuracy and extremely long-term stability.They exhibit several advantages over other non-resonant pressure sensors,including that the stable mechanical properties of the structure dominate the long-term drift,and the output is quasi-digital signal.A low-cost micromachined resonant pressure sensor with electrostatic excitation and capacitive detection is presented,which uses an improved dynamically balanced double-ended tuning fork resonator.The sensor chip is microfabricated through a simple yet reliable micromachining process based on a commercially available silicon-on-insulator wafer with only two masks,and hermetically encapsulated in a custom 16-pin kovar package at atmospheric pressure.Test results show that the quality factor is about 1250 at atmospheric pressure,which rises to above 50,000 below 5 Pa.The fundamental resonant frequency is approximately 35 kHz,with the static pressure sensitivity of 10 Hz/kPa.The base pressure range is from 3.4 kPa to 280 kPa absolute,with 1.25 times permitted overload full scale pressure.The precision is better than ±0.02%FS,and the temperature range is from-20℃ to 60℃.