GB2194333A - Detection method and device - Google Patents

Detection method and device Download PDF

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Publication number
GB2194333A
GB2194333A GB08616063A GB8616063A GB2194333A GB 2194333 A GB2194333 A GB 2194333A GB 08616063 A GB08616063 A GB 08616063A GB 8616063 A GB8616063 A GB 8616063A GB 2194333 A GB2194333 A GB 2194333A
Authority
GB
United Kingdom
Prior art keywords
fluid
chamber
light
attenuation
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08616063A
Other versions
GB8616063D0 (en
GB2194333B (en
Inventor
Samuel Christopher Rushforth
Frederick John Bryant
Eric Lionel Thomas
Anthony Krier
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electricity Council
Original Assignee
Electricity Council
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Electricity Council filed Critical Electricity Council
Priority to GB8616063A priority Critical patent/GB2194333B/en
Publication of GB8616063D0 publication Critical patent/GB8616063D0/en
Publication of GB2194333A publication Critical patent/GB2194333A/en
Application granted granted Critical
Publication of GB2194333B publication Critical patent/GB2194333B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16N—LUBRICATING
    • F16N29/00—Special means in lubricating arrangements or systems providing for the indication or detection of undesired conditions; Use of devices responsive to conditions in lubricating arrangements or systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/256—Arrangements using two alternating lights and one detector
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G01N21/534—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke by measuring transmission alone, i.e. determining opacity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/85—Investigating moving fluids or granular solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00—Features of devices classified in G01N21/00
    • G01N2201/06—Illumination; Optics
    • G01N2201/062—LED's
    • G01N2201/0621—Supply

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  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Engineering & Computer Science (AREA)
  • Biochemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Health & Medical Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Mechanical Engineering (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

A method of detecting a first fluid in a second fluid, for example water in oil, comprises passing a beam (A) of light having a wavelength which is selectively absorbed by the first fluid, through the second fluid, and measuring the attenuation of the beam (A) after passage through the second fluid. The method is carried out using a device having a second reference beam (8) which is not passed through the second fluid. The beams (A) and (B) may be modulated at different frequencies, electronic processing circuitry (10) containing filters tuned to the two frequencies. Cooling oil in electrical transformers and switchgear may be monitored using the device. <IMAGE>

Description

SPECIFICATION Detection method and device This invention relates to a detection method and device, and particularly to a method of detecting the presence of a first fluid in a second fluid, and a device for use in carrying out such method.
In electrical power supply systems equipment such as transformers and switchgear is often contained in an enciosure, wholly or partially immersed in oil both for cooling purposes and so that operation at high voltages can be achieved, the oil being a dielectric material.
Difficulties can arise if the oil in such anenclosure becomes contaminated with water since this will reduce the dielectric strength of the oil, and thus it is necessary to check such oil to determine any water content so that action can be taken before any difficulties arise.
According to this invention there is provided a method of detecting the presence of a first fluid in a second fluid, comprising passing a beam of light having a wavelength which is selectively absorbed by the first fluid through the second fluid, and measuring the attenuation of the beam after passage through the second fluid.
Preferably the attenuation of the beam is determined by comparison of the beam with a reference beam of light having said wavelength, which is not passed through the second fluid, in which case the two beams can be modulated at mutually different frequencies to enable discrimination therebetween.
Preferably the beam or beams of light are in the infrared region.
Also according to this invention there is provided a device for use in detecting the presence of a first fluid in a second fluid, comprising a housing containing a first chamber to receive the second fluid, and a second chamber sealed from the first chamber by an intermediate wall, and containing means to emit a beam of light having a wavelength which is selectively absorbed by the first fluid, the beam, in use of the device, passing through the intermediate wall into the first chamber to be reflected by a mirror defining a wall of the first chamber back through the intermediate wall to a receiver mounted in the second chamber, the receiver providing an output electrical signal representative of any attenuation of the beam by passage thereof through the second fluid in the first chamber, such attenuation being indicative of the presence of the first fluid in the second fluid.
Preferably the second chamber contains means to emit a reference beam of light having said wavelength, which reference beam is, in use of the device, reflected from the intermediate wall in the housing to the receiver to provide a reference electrical signal for comparison with that derived from the beam passed through the oil in the first chamber to determine said attenuation.
This invention will now be described by way of example with reference to the drawing which is a diagrammatic sectional side elevation view of a device according to the invention for use in carrying out the method of the invention.
Referring to the drawing, the device to be described is for use in detecting the presence of water in oil, and comprises a cylindrical housing 1 closed at one end by a fully silvered mirror 2 and divided into two chambers 3 and 4 by' an intermediate wall formed by a half-silvered mirror 5 which seals the first lower (as seen in the drawing) chamber 3 between the mirrors 2 and 5 from the second upper chamber 4.
The wall of the housing 1 about the lower chamber 3 is formed with holes 6 through which liquid can enter and flow through the chamber 3, assisted if necessary by an electric pump (not shown).
Mounted in the upper chamber 4 are two infrared radiation emitting photo-diodes 7 and 8 each of which emits a beam of infrared radiation at a wavelength which is selectively absorbed by water, a suitable wavelength being 1.85 microns.
The beam A from the diode 7 is modulated at a first frequency, and the diode 7 is arranged such that the beam A will pass through the transparent half of the mirror 5 to be reflected by the mirror 2 and returned through the mirror 5 to a receiver 9 mounted in the chamber 4 of the housing 1. The beam B from the diode 8 is modulated at a second frequency, and the diode 8 is arranged such that the beam B is reflected by the mirror 5 to the receiver 9.
The receiver 9 provides an electrical output signal which is passed by way of two filters (not shown), tuned to the first and second modulation frequencies respectively, so that the signals from the diodes 7 and 8 can be distinguished, to electronic processing circuitry 10 mounted in the chamber 4 of the housing 1. The circuitry 10 operates to compare the signals from the two diodes 7 and 8 thereby to determine any attenuation thereof. The circuitry 10 is connected by way of a cable 11 to a display in the form of a digital readout (not shown) calibrated to display water content in p.p.m. indicated by any attenuation determined by the circuitry 10.
For use of the device described above, the housing 1 is dipped into oil in a container, such that the oil enters and flows through the chamber 3. The circuitry is then energised such that the diodes 7 and 8 emit their beams of infrared radiation, the beam A passing through the oil in the chamber 3 on its way to the receiver 9. The beam A is thus attenuated by any water in the oil, and this attenuation will be detected by the circuitry 10. The beam B from the diode 8 does not pass through the oil on its way to the receiver 9, and serves as a reference for determining the attenuation of the beam A. The location of the diodes 7 and 8 close to each other avoids inaccuracies from drift due to temperature changes. Any attenuation determined by the circuitry 10 is transmitted over the cable 11 to the display where it is displayed on a scale reading, for example, from 10 to 500 p.p.m.
The device described above can be battery powered, and thus portable, for use in the field to determine any water content in oil in enclosures housing electrical power supply system transformers or switchgear, the housing being dipped directly into the oil in the enclosure. Otherwise the device can be used to determine any water content in a sample of oil transferred from its place of use to a container having the device mounted on the wall thereof.

Claims (15)

1. A method of detecting the presence of a first fluid in a second fluid, comprising passing a beam of light having a wavelength which is selectively absorbed by the first fluid through the second fluid, and measuring the attenuation of the beam after passage through the second fluid.
2. A method as claimed in Claim 1, in which the attenuation of the beam is determined by comparison of the beam with a reference beam of light having said wavelength, which is not passed through the second fluid.
3. A method as claimed in Claim 2, in which the two beams of light are modulated at mutually different frequencies.
4. A method as claimed in any preceding claim, in which the beam or beams of light are in the infrared region.
5. A device for use in detecting the presence of a first fluid in a second fluid, comprising a housing containing a first chamber to receive the second fluid, and a second chamber sealed from the first chamber by an intermediate wall and containing means to emit a beam of light having a wavelength which is selectively absorbed- by the first fluid, the beam, in use of the device, passing through the intermediate wall into the first chamber to be reflected by a mirror defining a wall of the first chamber back through the intermediate wall to a receiver mounted in the second chamber, the receiver providing an output electrical signal representative of any attenuation of the beam by passage thereof through the second fluid in the first chamber, such attenuation being indicative of the presence of the first fluid in the second fluid.
6. A device as claimed in Claim 5, in which the second chamber contains means to emit a reference beam of light having said wavelength, which reference beam is, in use of the device, reflected from the intermediate wall in the housing to the receiver to provide a reference electrical signal for comparison with that derived from the beam passed through the oil in the first chamber to determine said attenuation.
7. A device as claimed in Claim 6, in which the intermediate wall is constituted by a halfsilvered mirror.
8. A device as claimed in Claim 6 or Claim 7, in which said means to emit are photodiodes.
9. A device as claimed in any one of Claims 6 to 8, including means to modulate the two beams of light at mutually different frequencies.
10. A device as claimed in any one of Claims 5 to 9, in which the beam or beams of light emitted by said means to emit are in the infrared region.
11. A device as claimed in any one of Claims 5 to 10, in which the signal or signals from the receiver are processed by electronic circuitry contained in the second chamber of the housing.
12. A device as claimed in Claim 11 as dependent upon Claim 9, in which the signals from the receiver are passed to the circuitry by way of two filters tuned to said different frequencies respectively.
13. A device as claimed in Claim 11 or Claim 12, in which the electronic circuitry is connected by way of a cable to a display positioned outside the housing and arranged to display the amount of any first fluid in the second fluid in the first chamber of the housing.
14. A method of detecting the presence of a first fluid in a second fluid, substantialiy as hereinbefore described with reference to the drawing.
15. A device for use in detecting the presence of a first fluid in a second fluid, substantially as hereinbefore described with reference to the drawing.
GB8616063A 1986-07-01 1986-07-01 Detection method and device Expired - Fee Related GB2194333B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8616063A GB2194333B (en) 1986-07-01 1986-07-01 Detection method and device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8616063A GB2194333B (en) 1986-07-01 1986-07-01 Detection method and device

Publications (3)

Publication Number Publication Date
GB8616063D0 GB8616063D0 (en) 1986-08-06
GB2194333A true GB2194333A (en) 1988-03-02
GB2194333B GB2194333B (en) 1990-08-29

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Family Applications (1)

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GB8616063A Expired - Fee Related GB2194333B (en) 1986-07-01 1986-07-01 Detection method and device

Country Status (1)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0374523A2 (en) * 1988-12-23 1990-06-27 Heidelberger Druckmaschinen Aktiengesellschaft Method for monitoring centrally lubricated machine sets
WO1991016618A1 (en) * 1990-04-24 1991-10-31 The Foxboro Company On-line titration using colorimetric end point detection
US5402241A (en) * 1989-03-30 1995-03-28 The Foxboro Company Optical probe for fluid light transmission properties
DE4445668A1 (en) * 1994-12-21 1996-06-27 Euroferm Gmbh I Gr Device for measuring the partial pressure of gases dissolved in liquids
WO2001040701A3 (en) * 1999-11-30 2002-01-17 Mahle Filtersysteme Gmbh Oil system, in particular a hydraulic or lubricating oil system
DE102020114316A1 (en) 2020-05-28 2021-12-02 Voith Patent Gmbh System and method for supplying a lubrication point with lubricating oil

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB771531A (en) * 1952-03-20 1957-04-03 Saint Gobain Improvements in or relating to the detection and estimation of sulphur dioxide in a gaseous mixture
GB801227A (en) * 1955-12-20 1958-09-10 British Oxygen Co Ltd Photoelectric measurement of ozone concentrations
GB1479110A (en) * 1974-02-15 1977-07-06 Deutsche Forsch Luft Raumfahrt Method and device for detecting nitric oxide
GB2017905A (en) * 1978-02-23 1979-10-10 Tatnall M Apparatus for use in the monitoring of expired anaesthetic concentrations
GB2123547A (en) * 1982-07-12 1984-02-01 Akad Wissenschaften Ddr Ultraviolet spectral hygrometer for gas moisture determination
GB2136118A (en) * 1983-03-03 1984-09-12 Inst Francais Du Petrole A process and device for determining the composition of an alcohol-petrol mixture

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8609619D0 (en) * 1986-04-19 1986-05-21 Procal Analytics Gas analysis

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB771531A (en) * 1952-03-20 1957-04-03 Saint Gobain Improvements in or relating to the detection and estimation of sulphur dioxide in a gaseous mixture
GB801227A (en) * 1955-12-20 1958-09-10 British Oxygen Co Ltd Photoelectric measurement of ozone concentrations
GB1479110A (en) * 1974-02-15 1977-07-06 Deutsche Forsch Luft Raumfahrt Method and device for detecting nitric oxide
GB2017905A (en) * 1978-02-23 1979-10-10 Tatnall M Apparatus for use in the monitoring of expired anaesthetic concentrations
GB2123547A (en) * 1982-07-12 1984-02-01 Akad Wissenschaften Ddr Ultraviolet spectral hygrometer for gas moisture determination
GB2136118A (en) * 1983-03-03 1984-09-12 Inst Francais Du Petrole A process and device for determining the composition of an alcohol-petrol mixture

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0374523A2 (en) * 1988-12-23 1990-06-27 Heidelberger Druckmaschinen Aktiengesellschaft Method for monitoring centrally lubricated machine sets
EP0374523A3 (en) * 1988-12-23 1990-08-16 Heidelberger Druckmaschinen Aktiengesellschaft Method for monitoring centrally lubricated rotary press machine sets
US4967880A (en) * 1988-12-23 1990-11-06 Heidelberger Druckmaschinen Ag Process and apparatus for monitoring lubricating oil water content for rotary printing presses
US5402241A (en) * 1989-03-30 1995-03-28 The Foxboro Company Optical probe for fluid light transmission properties
WO1991016618A1 (en) * 1990-04-24 1991-10-31 The Foxboro Company On-line titration using colorimetric end point detection
DE4445668A1 (en) * 1994-12-21 1996-06-27 Euroferm Gmbh I Gr Device for measuring the partial pressure of gases dissolved in liquids
WO2001040701A3 (en) * 1999-11-30 2002-01-17 Mahle Filtersysteme Gmbh Oil system, in particular a hydraulic or lubricating oil system
US6746610B2 (en) 1999-11-30 2004-06-08 Mahle Filtersysteme Gmbh Oil system, in particular a hydraulic or lubricating oil system
DE102020114316A1 (en) 2020-05-28 2021-12-02 Voith Patent Gmbh System and method for supplying a lubrication point with lubricating oil

Also Published As

Publication number Publication date
GB8616063D0 (en) 1986-08-06
GB2194333B (en) 1990-08-29

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Legal Events

Date Code Title Description
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950701