EP0079988A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical fibre transmission instrumentation
Assignee: Individual
•
Filing: 1981-11-23
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Granted: —
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Expires: 2001-11-23
Abstract
Abstract The invention relates to remote sensing instrumentation wherein the value of a physical parameter e.g. pressure or temperature being monitored by a primary sensor or detector is transmitted to an indicator/control unit by light signals through optical fibres rather than the normal electrical signals through cables. An optical coupling element which is advantageously in the form of a mechanical/optical converter (1) receives an input (16) from a light source (7, 27) via an optical fibre (3) and produces a reference output (18) and an active output (17) which are returned via optical fibres (5) and (4) respectively to a comparator (8). The comparator derives an electrical signal proportional to the response of the primary detector (2).
Inventors
- 👤 Dennis William Burt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 18:11
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/16; G01D; G01D5/00; G01D5/26; G01D5/268; G01L; G01L11/00; G01L11/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
269 words
Apparatus for sensing or measurement of a physical parameter, which apparatus comprises an optical coupling element associated with, or adapted to be associated with, a detector responsive to the parameter to be sensed or measured; a control unit including an indicating instrument and a light source; and a plurality of optical fibres which, at least when the apparatus is in use, extend between the control unit and the optical coupling element and provide optical communication therebetween, wherein (1) the optical coupling element includes an optical input from the light source, means for modifying light received at the input in accordance with the output of the detector which in'use is associated with the optical coupling element, a first output for light modified in this way and a second output for an unmodified, reference light; (2) a first optical fibre or a first group of optical fibres serve(s) to transmit the light from the light source to the optical coupling element, a second optical fibre or a second group of optical fibres serve(s) to transmit light from the first output of the optical coupling element to the control unit and a third optical fibre or a third group of optical fibres serve(s) to transmit light from the second output of the optical coupling element to the control unit; (3) the control unit comprises means for comparing light received from the first and second outputs of the optical coupling element and for deriving therefrom a measurement or indication pertaining to the parameter being investigated; and (4) said indicating instrument is adapted to display the measurement or indication derived from the comparator means.
Claim 2
Dependent Claim
269 words
Apparatus for sensing or measurement of a physical parameter, which apparatus comprises an optical coupling element associated with, or adapted to be associated with, a detector responsive to the parameter to be sensed or measured; a control unit including an indicating instrument and a light source; and a plurality of optical fibres which, at least when the apparatus is in use, extend between the control unit and the optical coupling element and provide optical communication therebetween, wherein (1) the optical coupling element includes an optical input from the light source, means for modifying light received at the input in accordance with the output of the detector which in'use is associated with the optical coupling element, a first output for light modified in this way and a second output for an unmodified, reference light; (2) a first optical fibre or a first group of optical fibres serve(s) to transmit the light from the light source to the optical coupling element, a second optical fibre or a second group of optical fibres serve(s) to transmit light from the first output of the optical coupling element to the control unit and a third optical fibre or a third group of optical fibres serve(s) to transmit light from the second output of the optical coupling element to the control unit; (3) the control unit comprises means for comparing light received from the first and second outputs of the optical coupling element and for deriving therefrom a measurement or indication pertaining to the parameter being investigated; and (4) said indicating instrument is adapted to display the measurement or indication derived from the comparator means.
Claim 3
Dependent Claim
39 words
Apparatus as claimed in claim 1, wherein the said optical coupling element is such that the optical path of light travelling from the input to the first output thereof is varied in accordance with the output of the detector.
Claim 4
Dependent Claim
43 words
Apparatus as claimed in claim 1, wherein the said optical coupling element is such that the intensity of light travelling through the optical coupling element from the input to the first output thereof is varied in accordance with the output of the detector.
Claim 5
Dependent Claim
43 words
Apparatus as claimed in claim 1, wherein the said optical coupling element is such that the phase of light travelling through the optical coupling element from the input to the first output thereof is varied in accordance with the output of the detector.
Claim 6
Dependent Claim
43 words
Apparatus as claimed in claim 1, wherein the said optical coupling element is such that the polarisation of light travelling through the optical coupling element from the input to the first output thereof is varied in accordance with the output of the detector.
Claim 7
Dependent Claim
85 words
Apparatus as claimed in claim 3, wherein the optical coupling element includes a block having a first region of relatively high optical transparency and a second region of relatively low optical transparency, the block being positioned so that the region of relatively low optical transparency is caused to occupy a proportion of the optical path between the input and the first output of the optical coupling element which proportion is dependent upon the output of the detector with which the optical coupling element is associated.
Claim 8
Dependent Claim
33 words
Apparatus as claimed in any preceding claim, wherein the optical coupling element is connected to the detector with which it is associated via a bourdon tube, a diaphragm, a torque tube or bellows.
Claim 9
Dependent Claim
18 words
Apparatus as claimed in any preceding claim, wherein the light source is adapted to produce pulses of light.
Claim 10
Dependent Claim
130 words
A remote sensing equipment or instrument using a plurality of optical fibres between a sensor and an indicating instrument, wherein one fibre is used to transmit light from the indicating instrument to the sensor; means are provided at the sensor to modify this light in accordance with a physical parameter being sensed by the sensor and to transmit this modified light back to the indicating instrument through one or more of the remaining fibres and also to transmit an unmodified reference light back to the indicating instrument through a further one or more of the remaining optical fibres; means are provided to compare the modified light with the unmodified reference light; and the result of this comparison is represented as the value of the physical property experienced by the sensor.
Claim 11
Dependent Claim
130 words
A remote sensing equipment or instrument using a plurality of optical fibres between a sensor and an indicating instrument, wherein one fibre is used to transmit light from the indicating instrument to the sensor; means are provided at the sensor to modify this light in accordance with a physical parameter being sensed by the sensor and to transmit this modified light back to the indicating instrument through one or more of the remaining fibres and also to transmit an unmodified reference light back to the indicating instrument through a further one or more of the remaining optical fibres; means are provided to compare the modified light with the unmodified reference light; and the result of this comparison is represented as the value of the physical property experienced by the sensor.
Claim 12
Dependent Claim
62 words
Apparatus as claimed in claim 9, wherein the means provided at the sensor for modifying the light is an optical couple manufactured either from solid or flexible material and linked to a bourdon tube, a diaphragm, bellows or similar physical sensing device such that the optical path through the optical couple is directly varied by the physical parameter sensed by the device.
Claim 13
Dependent Claim
89 words
Apparatus as claimed in claim 9 or 10, wherein light of constant value is sent from the indicating instrument through one optical fibre to the sensor and is returned both (a) unmodified and (b) modified in value by the physical parameter sensed by the sensor back through a respective one or more of the remaining fibres to the indicating instrument where means are provided to compare the unmodified and modified values, the result of the comparison being displayed as the value of the physical parameter sensed by the sensor.
Claim 14
Dependent Claim
87 words
Apparatus as claimed in claim 9, wherein pulsed light is sent from the indicating instrument through one optical fibre to the sensor and is returned both (a) unmodified and (b) modified in phase by the physical parameter sensed by the sensor back through a respective one or more of the remaining fibres to the indicating instrument where means are provided to compare the difference in phase between the unmodified and modified pulses this difference being displayed as the value of the physical parameter sensed by the sensor.
Claim 15
Dependent Claim
24 words
Apparatus as claimed in any preceding claim, wherein the light source emits electromagnetic radiation in the visible, infra-red, or ultra-violet regions of the spectrum.
Claim 16
Dependent Claim
18 words
Apparatus according to claim 1 or 9, and substantially as hereinbefore described with reference to the accompanying drawing.
References Cited (Backward Citations)
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