GB2303444A - Method of and apparatus for detecting moisture - Google Patents

Method of and apparatus for detecting moisture Download PDF

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Publication number
GB2303444A
GB2303444A GB9514316A GB9514316A GB2303444A GB 2303444 A GB2303444 A GB 2303444A GB 9514316 A GB9514316 A GB 9514316A GB 9514316 A GB9514316 A GB 9514316A GB 2303444 A GB2303444 A GB 2303444A
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GB
United Kingdom
Prior art keywords
wavelength
radiation
water
dampness
specifically absorbed
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
GB9514316A
Other versions
GB9514316D0 (en
GB2303444B (en
Inventor
Fali Minocher Dadachanji
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.)
GE Protimeter Ltd
Original Assignee
Protimeter PLC
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 Protimeter PLC filed Critical Protimeter PLC
Priority to GB9514316A priority Critical patent/GB2303444B/en
Publication of GB9514316D0 publication Critical patent/GB9514316D0/en
Publication of GB2303444A publication Critical patent/GB2303444A/en
Application granted granted Critical
Publication of GB2303444B publication Critical patent/GB2303444B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • 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
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3554—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for determining moisture content

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

Description

Agents Ref: P9898GB-H/JCC/er Title: METHOD OF AND APPARATUS FOR DETECTING MOISTURE This invention relates to a method and apparatus for detecting moisture or dampness on walls and other surfaces of buildings, and which method and apparatus have some advantages as compared with known methods and apparatus.
In current practice it is normal to detect or assess moisture or dampness in buildings or other structures by techniques which involve touching the materials of such buildings or other structures, for example by measuring the conductivity or capacitance of the walls of a building, which conductivity or capacitance is enhanced by an excess of moisture on or in the walls. In some cases it would be advantageous if detection or measurement of dampness could be made remotely, for example in the case of high ceilings or under bridges where contact with the surface to be checked is difficult, e.g. because it is necessary to use scaffolding or ladders to enable an appropriate instrument to be brought into contact with the surface concerned.
It is an object of the present invention to provide a method of assessing moisture content or dampness remotely.
According to one aspect of the invention, there is provided a method of remotely assessing moisture content or dampness of a body presenting an exposed surface, comprising comparing radiation from said surface at a wavelength specifically absorbed by water and at a wavelength not specifically absorbed by water.
It is another object of the invention to provide apparatus for assessing moisture content or dampness remotely. According to this aspect of the invention, there is provided apparatus for remotely assessing moisture content or dampness of a body presenting an exposed surface including an optical system for directing onto a sensor electromagnetic radiation from a predetermined region of a field of view of the apparatus and means for comparing the intensities of the respective signals due to radiation received at a wavelength or wavelength band specifically absorbed by water and at a wavelength or wavelength band not specifically absorbed by water.
It is well-known that all surfaces at ambient temperatures have emissions in the infrared region. It is also well-known that water has a strong absorbing affect at certain wavelengths in the infrared region.
In a preferred embodiment of the invention, apparatus for assessing dampness or moisture content remotely includes means for measuring all the radiation from a surface in a wide I.R. band using any of a number of devices which can measure the emissions in the infrared region. The apparatus is also provided with a series of filters and/or other optical arrangements making it possible to measure the emissions at precisely the wavelength which is normally absorbed by water. A comparison of these two readings will give an indication of the amount of water present. Such a measurement could be made by arranging the optics in the form of a portable device which can be carried to a site where testing is to be carried out. A number of readings could be taken over an area where a plot can be made of the two readings above.
The part of the area showing the highest differences would normally be the wettest portion of the area to be measured or scanned.
It will be understood that in a practical embodiment the device embodying the invention is preferably arranged so that respective I.R. sensors mounted in a suitable casing for the instrument simultaneously receive, from the same region of the "field of view" of the instrument, unfiltered I.R. radiation and I.R. radiation filtered by filters mounted in the housing, or arranged so that the I.R. radiation reaches the two sensors through filters for different wavelengths or bands of wavelengths.
In either case, processing circuitry within the housing processes the signals from the two sensors and makes a comparison between the signals from said sensors, which forms the basis for the moisture or dampness detection, the processing means providing an output signal, for example a meter reading or digital display reading directly significant of moisture or dampness level.
In another arrangement it is possible to shine an infrared beam at the target to be assessed, the beam comprising infrared radiation of, say, two wavelengths, one being a wavelength which is strongly absorbed by water and the other being a reference wavelength not selectively absorbed by water, and to measure the relative strengths of the wavelengths in the reflected radiation to arrive at an indication of the dampness of the surface at which the instrument is directed.
A device embodying the invention is particularly useful as a surveying tool to find indications of excess moisture on walls and parts of buildings without the need to make contact with the surface of such walls or parts.

Claims (7)

CLAIMS:
1. A method of remotely assessing moisture content or dampness of a body presenting an exposed surface, comprising comparing radiation from said surface at a wavelength specifically absorbed by water and at a wavelength not specifically absorbed by water.
2. A method according to Claim 1, which is passive in the sense that radiation emitted by the body is so compared.
3. A method according to Claim 1, wherein such radiation is beamed at said surface and relative intensities of the reflected radiation of said wavelength are compared.
4. Apparatus for remotely assessing moisture content or dampness of a body presenting an exposed surface including an optical system for directing onto a sensor electromagnetic radiation from a predetermined region of a field of view of the apparatus and means for comparing the intensities of the respective signals due to radiation received at a wavelength or wavelength band specifically absorbed by water and at a wavelength or wavelength band not specifically absorbed by water.
5. Apparatus according to Claim 4, including a respective sensor for each of said wavelength or wavelength bands and means for comparing the signals from said sensor.
6. Apparatus according to Claim 4 or Claim 5, including means for directing electromagnetic radiation onto said predetermined region of the field of view.
7. Any novel feature or combination of features disclosed herein.
GB9514316A 1995-07-13 1995-07-13 Method of and apparatus for detecting moisture Expired - Fee Related GB2303444B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9514316A GB2303444B (en) 1995-07-13 1995-07-13 Method of and apparatus for detecting moisture

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9514316A GB2303444B (en) 1995-07-13 1995-07-13 Method of and apparatus for detecting moisture

Publications (3)

Publication Number Publication Date
GB9514316D0 GB9514316D0 (en) 1995-09-13
GB2303444A true GB2303444A (en) 1997-02-19
GB2303444B GB2303444B (en) 1999-03-10

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB9514316A Expired - Fee Related GB2303444B (en) 1995-07-13 1995-07-13 Method of and apparatus for detecting moisture

Country Status (1)

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GB (1) GB2303444B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2334097A (en) * 1998-02-06 1999-08-11 British Gas Plc System to detect the presence of water on a surface
GB2345540A (en) * 1999-01-07 2000-07-12 Infrared Integrated Syst Ltd Multiple filter based detector array
WO2000079235A1 (en) * 1999-06-23 2000-12-28 Patrick Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy
GB2395784A (en) * 1999-06-23 2004-06-02 Patrick Toomey Water and fungus detection methods for structures using electromagnetic radiation spectroscopy

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1013171A (en) * 1961-10-09 1965-12-15 Gen Electric Method and apparatus for continuously indicating the amount of a substance in a basematerial
GB1271439A (en) * 1969-02-17 1972-04-19 Measurex Corp Apparatus for measuring the amount of a substance that is associated with a base material
US3675019A (en) * 1971-03-19 1972-07-04 Measurex Corp Apparatus for measuring the amount of a substance that is associated with a base material
US3821553A (en) * 1972-11-17 1974-06-28 Measurex Corp Dual wavelength moisture gauge having automatic gain control
GB1416619A (en) * 1972-10-27 1975-12-03 Measurex Corp Moisture gauge with opacity type compensation
US4306151A (en) * 1978-02-03 1981-12-15 Measurex Corporation Method of measuring the amount of substance associated with a material in the presence of a contaminant

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1013171A (en) * 1961-10-09 1965-12-15 Gen Electric Method and apparatus for continuously indicating the amount of a substance in a basematerial
GB1271439A (en) * 1969-02-17 1972-04-19 Measurex Corp Apparatus for measuring the amount of a substance that is associated with a base material
US3675019A (en) * 1971-03-19 1972-07-04 Measurex Corp Apparatus for measuring the amount of a substance that is associated with a base material
GB1416619A (en) * 1972-10-27 1975-12-03 Measurex Corp Moisture gauge with opacity type compensation
US3821553A (en) * 1972-11-17 1974-06-28 Measurex Corp Dual wavelength moisture gauge having automatic gain control
US4306151A (en) * 1978-02-03 1981-12-15 Measurex Corporation Method of measuring the amount of substance associated with a material in the presence of a contaminant

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2334097A (en) * 1998-02-06 1999-08-11 British Gas Plc System to detect the presence of water on a surface
GB2334097B (en) * 1998-02-06 2002-08-07 British Gas Plc Method and apparatus to detect the presence of water on a surface
GB2345540A (en) * 1999-01-07 2000-07-12 Infrared Integrated Syst Ltd Multiple filter based detector array
GB2345540B (en) * 1999-01-07 2001-03-21 Infrared Integrated Syst Ltd Spectrometer/spectrophotometer using multiple filter based detector array
WO2000079235A1 (en) * 1999-06-23 2000-12-28 Patrick Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy
GB2367616A (en) * 1999-06-23 2002-04-10 Patrick Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy
US6633038B2 (en) * 1999-06-23 2003-10-14 Patrick J. Toomey Methods of detecting presence of water in structure based on principle of luminescence
GB2395784A (en) * 1999-06-23 2004-06-02 Patrick Toomey Water and fungus detection methods for structures using electromagnetic radiation spectroscopy
GB2367616B (en) * 1999-06-23 2004-06-16 Patrick Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy
GB2395784B (en) * 1999-06-23 2004-07-28 Patrick Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy
US6841781B2 (en) * 1999-06-23 2005-01-11 Patrick J. Toomey Water detection and source identification methods for structures using electromagnetic radiation spectroscopy

Also Published As

Publication number Publication date
GB9514316D0 (en) 1995-09-13
GB2303444B (en) 1999-03-10

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 20070713