Development of a pressure transducer for usage in high-temperature and vibration environments. Phase 1: Feasibility investigation

The objective of the phase 1 project is to determine the feasibility of developing a highly accurate, low range pressure transducer that is suitable for measurement in environments where high vibrations, high temperatures and varying line pressures create problems for presently available transducers. The primary sensor is an elastic metal diaphragm that forms one plate of a capacitor; the other plate is fixed with respect to the diaphragm. An electronic circuit converts the diaphragm deflections, induced by a pressure force, into voltage variations that are then sampled by a microprocessor, which is to be developed in phase 2. Because of the small oscillating mass of the diaphragm, the transducer has a high natural frequency and is largely insensitive to externally induced vibrations. The simple configuration of the capacitive transducer is potentially very large overloads with appropriate installation of an overload stop between the two plates. In comparison with other types of pressure sensors, the capacitive transducer concept offers an unusual amount of design flexibility for a wide range of operational conditions. Phase 1 research demonstrated the feasibility of the capacitive transducer concepts, as well as its capability to meet and potentially exceed all DoD requirements for transducer performance.