Sensor apparatus
First Claim
1. A sensor apparatus comprising a plurality of resonant sensors each comprising a vibrating element, wherein the resonant frequency of each sensor shifts within a range dependent on at least the parameter sensed by the respective sensor, the ranges of each of the sensors being different.
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Accused Products
Abstract
A measurement head particularly for borehole use can measure multiple parameters with no electronics in the head and only a single conductor cable. Double-ended tuning forks (26, 28 and 38, 40) in the head are arranged to respond to different parameters such as temperature and pressure by adjusting their resonant frequencies. A drive signal on the conductor (50) is applied to transducers (30, 32, 42, 44) on all the tuning forks and those whose instantaneous resonant frequency is close will resonate. The signal is removed and the transducers return a decaying signal at the resonant frequency along the conductor. Other drive frequencies are tried, to locate the other sensors whose frequency ranges are separate.
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Citations
16 Claims
- 1. A sensor apparatus comprising a plurality of resonant sensors each comprising a vibrating element, wherein the resonant frequency of each sensor shifts within a range dependent on at least the parameter sensed by the respective sensor, the ranges of each of the sensors being different.
- 2. A sensor apparatus comprising a plurality of resonant sensors each of whose operating frequency shifts within a range dependent on at least the parameter sensed by the respective sensor, the ranges of each of the sensors being different all of the sensors being supplied by a single signal conductor.
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15. Sensor apparatus for remote parameter measurement in boreholes comprising a measurement head, a cable leading from the measurement head to remote instrumentation, a conductor within the cable leading to transducers within the measurement head, each of which drive and are driven by a resonating element also within the measurement head and whose resonant frequency responds to the measured parameter.
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16. Sensor apparatus substantially as herein described with reference to and/or as illustrated in the accompanying drawings.
Specification