Remote temperature-compensated pressure sensor

Claim 2

A remote pressure sensor system for providing a temperature compensated pressure measurement, the system including a first vibrational transducer whose resonant frequency corresponds to an applied pressure, a second vibrational transducer the characteristics of which are a function of temperature, first optical means for setting the transducers into a state of vibration, second optical means for interrogating the first and second transducers so as to determine their respective resonant frequencies, and means for calculating from the frequencies of the two transducers a temperature compensated measure of the pressure applied to the first transducer.

Claim 3

A remote pressure sensor for providing a temperature compensated pressure measurement, the system including a first vibrational transducer whose resonant frequency corresponds to an applied pressure, a second vibrational transducer similar in construction to the first transducer and whose resonant frequency is a function only of temperature, a first, pulsed, optical source whereby each transducer is maintained in a state of vibration at its respective resonant frequency, a second, continuous, optical source coupled to the transducers whereby an optical signal modulated with each transducer frequency is derived, means for determining the frequency of each said modulation and for calculating therefrom a temperature compensated measure of a pressure to which the first transducer is exposed, and means for deriving from each said modulation a control signal whereby the pulsed source is operated so as to derive each said transducer at its respective resonant frequency.

Claim 4

A remote pressure sensor for providing a temperature compensated pressure measurement, the system including a first vibrational transducer whose resonant frequency corresponds to an applied pressure, a second vibrational transducer similar in construction to the first transducer and whose resonant frequency is a function only of temperature, a first, pulsed, optical source whereby each transducer is maintained in a state of vibration at its respective resonant frequency, a second, continuous, optical source coupled to the transducers whereby an optical signal modulated with each transducer frequency is derived, means for determining the frequency of each said modulation and for calculating therefrom a temperature compensated measure of a pressure to which the first transducer is exposed, and means for deriving from each said modulation a control signal whereby the pulsed source is operated so as to derive each said transducer at its respective resonant frequency.

Claim 5

A remote sensor system as claimed in claim 1 or 2, wherein each said transducer includes first and second elongate members each supported on stretched filaments whereby that element can vibrate, said elements being coupled together so as to vibrate in antiphase.

Claim 6

A remote sensor system as claimed in claim 1, 2 or 3, wherein optical signals are carried to and from the first and second transducers via a single optical fibre.

Claim 7

A remote sensor system as claimed in claim 4 or 5 wherein said first and second transducers are mounted in a common evacuated housing.

Claim 8

A temperature compensated remote pressure sensor system substantially as described herein with reference to and as shown in the accompanying drawings.

Claim 9

A temperature compensated remote pressure sensor system substantially as described herein with reference to and as shown in the accompanying drawings.