Electric Power Research Institute Incorporated

Fred G Geil

John H Thompson

George F Gannon, Jr

Disclosed is a mechanical filter including a resonator mounted within a housing. A first acoustical waveguide extends through a bushing into the housing. Elastomer material fills the bushing and surrounds the first waveguide therein. A compliant member in the form of a bellows having an open end and a closed end is provided in the housing with the open end attached to the housing wall. The first acoustical waveguide is attached to the interior surface of the closed end of bellows, and a second acoustical waveguide is attached to the exterior surface of the closed end of the bellows and to the resonator. The compliant member provides coupling of the first and second waveguides and a hermetic seal.

Mechanical filter and method of acoustically coupling waveguides therein

The temperature of an environment is determined by measuring the acoustical response of a temperature sensitive two mode resonator placed in the environment. Two variable frequency signals are generated and applied to the resonator, and the two resonant frequencies of the resonator are determined. Frequency difference of the two frequencies is determined, and if the difference lies within a substantially uniform frequency range, the environment temperature is calculated from at least one of the frequencies. If the difference lies outside of the substantially uniform frequency range, then at least one of the two signals is spurious and no temperature calculation is made.

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Annapolis, MD, United States of America

Fred G Geil