GB2395784A

GB2395784A - Water and fungus detection methods for structures using electromagnetic radiation spectroscopy

Info

Publication number: GB2395784A
Application number: GB0403981A
Authority: GB
Inventors: Patrick Toomey
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-23
Filing date: 2000-06-22
Publication date: 2004-06-02
Anticipated expiration: 2020-06-22
Also published as: GB0403981D0; GB2396006A; GB2395784B; GB0405332D0; GB2396006B

Abstract

A method of the present invention includes exposing a structure to first electromagnetic radiation including at least one wavelength absorbed by a predetermined substance that is to be detected. Such substance can be water, a water-soluble substance, or fungi, the presence of which can be a significant problem in a structure such as a house or building. The method includes sensing second electromagnetic radiation from the structure, the second radiation based on the first radiation. The method also includes determining whether the substance is present in the structure, based on the sensed second radiation. If the substance to be detected is water and the determining step reveals a water-suspect area in the structure, the method can include testing the water-suspect area of the structure to determine whether water is present therein. If water is confirmed by the determination to be present in the structure, the method can include a step of determining the source of the water.

Description

WATER DETECTION AND SOURCE IDENTIFICATION METHODS FOR

STRUCTURES USING ELECTROMAGNETIC RADIATION

SPECTROSCOPY

Technical Field

5 The invented methods are directed to the detection and identification of the source of a water problem in a house' building or other structure. The invented methods are further directed to the detection of mold and fungi which inhabit moist predetermined areas of structures, and which can pose health concerns to persons living or working in their presence.

10 Background Art

The presence of a water problem in a structure is often difficult to detect before damage becomes so extensive that it is apparent to the unaided eye. In many cases, water seeps inside of a wall, ceiling, floor, roof or foundation of a structure such as a building or house, and causes widespread damage before the problem is 15 noticeable. By the time the water damage is visible, repairs to fix the structure are often far more costly than they would be if the water problem could be detected at an earlier stage. It would therefore be desirable to detect the presence of a water problem in a structure at a relatively early stage in its development so that such problem may be more readily corrected, possibly at greatly reduced expense.

20 in addition, numerous home and building owners have incurred the expense and inconvenience of repeatedly repairing a structure in an effort to correct a water problem, only to find the same problem recurring after repairs are made. It would be desirable to detect the presence of moisture in a structure, even in areas not visible to the unaided eye. to properly identify the source of a water problem so that effective 25 repair measures can be used to correct the water problem.

Another problem that is related to this invention concerns the limited area covered by most conventional moisture-detection devices such as capacitance meters. More specifically, the coverage predetermined area of such devices is generally less than one-hundred centimeters. The use of such devices to detect 30 moisture in a structure containing hundreds to many thousands of square meters is

clearly impractical. It would be desirable to provide a method capable of detecting moisture in relatively large areas of a structure with less need to reposition moisture detection equipment used to scan such areas. It would also be desirable to provide the capability to detect moisture in relatively large areas of a structure so that 5 inspection of a structure can be performed more rapidly than is possible with conventional devices and techniques.

Apart from the damage caused by water directly by rotting or otherwise deteriorating the material composing a structure, the presence of water in a structure can lead to many other problems. For example, pests such as termites are attracted to 10 moist wood in structures. Termites are capable of undermining a structure in a short period of time. The detection of a water problem in a structure, even if latent, would therefore be beneficial to stop or prevent pest infestation in a structure. Other problems associated with the presence of moisture in a structure include the so-called "sick home" syndrome. More specifically, moist and dark areas of a 15 structure such as a house or building often provide environments conducive to growth of fungi or molds to which many persons are allergic. Numerous instances have been reported in which persons living in houses or working in buildings have been made ill by fungi growing in the structure, in some cases resulting in death. In an effort to correct a water problem involving Fungi, some building owners have 20 spent in excess of the original building cost. It would therefore be desirable to detect and correct a water problem not only to prevent damage caused directly by water in a structure such as by rotting, but also to allow detection and correction of such problem to eliminate the indirect consequences of a water problem, such as pest or mold and fungi infestation.

25 Also related to the prescut invention is the general field of spectroscopy.

Spectroscopy is basically the study of how electromagnetic radiation interacts with matter. Generally speaking, spectroscopy can be performed in one of two techniques. In the first technique, a substance is exposed with electromagnetic radiation generally with a broad spectrum of wavelengths. The substance will absorb 30 electromagnetic radiation energy at discrete wavelengths which are highly indicative -2

of the identity of the substance, particularly if its atomic structure is relatively simple. An unknown substance can therefore be identified by exposing the substance with a broad spectrum of electromagnetic radiation wavelengths and determining those wavelengths at which the substance absorbs electromagnetic radiation energy, 5 i.e., its absorption spectra. The second technique involves the excitation of a substance with electromagnetic radiation or other form of energy. The substance can absorb the electromagnetic radiation and be brought to an excited state. Upon returning to its ground state, the substance emits radiation at certain discrete wavelengths that are highly characteristic of the substance. An unknown substance 10 can therefore be identified by its emission spectra. The emission wavelengths of a substance generally closely correspond to its absorption wavelengths, but will generally also include additional wavelengths that are not included in the substance's absorption spectrum. While spectroscopy is a useful science and has been used widely in many different applications, its use relative to structures such as a building 15 or house to detect a water problem, substances that indicate the source of the water problem, or mold and fungi, has not been known.

Disclosure of the Invention

An object of the invention is to detect the existence of a water problem in a structure. 20 Another, more specific object of the invention is to detect a water problem in a structure at a relatively early stage, even if the problem is latent, so that the water problem can be corrected before the structure incurs relatively extensive damage requiring costly repairs.

A farther object of the invention is to correctly identify the source of a water 25 problem in a structure to permit appropriate corrective action and/or repairs to be made to fix the probleni.

An additional object of the invention is to sense the presence of water over a relatively large area of the structure to reduce the need to reposition testing equipment and to permit the structure to be scanned in a relatively rapid manner.

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Another object of the invention is to effectively detect and identify the source of a water problem so that such problem can be corrected to reduce likelihood of infestation by termites or other pests, or molds or other fungi.

A further object of the invention is to effectively detect and identify the S presence of mold or fungi in a structure.

The present invention overcomes the above-noted disadvantages, and attains the objects and advantages set forth above. Broadly stated, the method of the present invention includes exposing a predetermined area of the structure with electromagnetic radiation including at least one wavelength that is significantly 10 absorbed by a predetermined substance such as water, a water-soluble substance such as carbonate, phosphate, sulfate, or chloride minerals, or fungi which grows in moist areas of a structure. The method also includes sensing the electromagnetic radiation from the exposed predetermined area of the structure, which results from the radiation used to expose the structure. The method also includes determining 15 whether the substance is present in the structure, based on the sensed electromagnetic radiation.

A relatively specific embodiment of the method exposing a predetermined area of the structure with electromagnetic radiation including at least one wavelength that is significantly absorbed by water. The method also includes sensing the 20 electromagnetic radiation from the exposed area of the structure, the sensed radiation based on the radiation used to expose the area of the structure. The method also includes determining whether the exposed area of the structure includes a water-suspect area, based on the sensed electromagnetic radiation. If the determination reveals the presence of a water-suspect area in the structure, the 25 method can include testing the water-suspect area of the structure to determine whether water is in fact present therein. If so, the method can include determining the source of the water. Proper identification of the source of a water problem permits appropriate measures to be taken to correct the water problem.

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Another relatively specific embodiment of the method can be used to detect whether a water-soluble substance (such as carbonate, phosphate, sulfate, or chloride minerals) is present in the structure, indicating that ground water is the likely source of water intrusion in the structure. Conversely, the absence of such water-soluble 5 substance is highly indicative that the water source is not ground water. The method includes exposing a predetermined area of the structure with electromagnetic radiation including at least one wavelength significantly absorbed by the water-soluble substance. The method also includes sensing electromagnetic radiation from the exposed area of the structure, the sensed radiation based on the radiation 10 used to expose the structure. The method also includes determining whether the water-soluble substance is present in the structure, based on the sensed electromagnetic radiation. The method can include determining that the source of water is ground water if the water-soluble substance is present in the exposed predetermined area of the structure. The method can also include determining that 15 the source of the water is not ground water if the water-soluble substance is not present in the exposed predetermined area of the structure.

Another relatively specific embodiment of the method includes exposing a predetermined area of a structure with electromagnetic radiation including at least one wavelength significantly absorbed by fungi. The method also includes sensing 20 electromagnetic radiation from the exposed area of the structure, the sensed radiation based on the radiation used to expose the structure. The method also includes determining whether fungi is present in the structure, based on the sensed electromagnetic radiation.

These together with other objects, features and advantages of the invention 25 will become subsequently apparent, and reside in the details of construction and operation as more-fully hereinafter described and claimed, reference being made to the accompanying drawings, forming a part hereof wherein like numerals refer to like parts throughout the several views.

Brief Description of the Drawings

Fig. 1 is a view of a first arrangement of a system that can be used to perform the invented methods; Fig. 2 is a view of a second arrangement of the system; 5Fig. 3 is a flow chart of a general method of the invention; Fig. 4 is a general flow chart of an embodiment of the method for detecting the presence of water in a structure; Figs. 5A and 5B are relatively specific flow charts of an embodiment of the method for detecting the presence of water in a structure which uses an exposure 10 wavelength(s) including at least one wavelength significantly absorbed by water, and a reference wavelength including at least one wavelength not significantly absorbed by water; Figs. 6A and 6B are relatively specific flow charts of an embodiment of the method for detecting the presence of water in a structure which uses exposure 15 wavelengths for both water and water vapor; Fig. 7 is a flow chart of an embodiment of the method for determining whether a water-soluble substance is present in a structure; Figs. 8A and 8B are relatively specific flow charts of an embodiment of the method for detecting the presence of a water-soluble substance in a structure; 20 Fig. 9 is a flow chart of an embodiment of the method for detecting the presence of fungi in a structure; and Figs. IOA and 1OB are relatively specific flow charts of an embodiment of the method for detecting fungi in a structure.

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Modes for Carrying out the Invention As used herein, the following terms and phrases have the following meanings: "A radiation wavelength that is significantly absorbed by water" means a radiation wavelength that water absorbs to a degree that can be sensed and 5 distinguished as characteristic of water. As is well understood in the field of

spectroscopy, the wavelength significantly absorbed by water is preferred to be at or near the center of a peak or maximum in the absorption spectrum of water.

"A radiation wavelength that is not significantly absorbed by water" means a radiation wavelength at or near the center of a valley or minima in the absorption I Q spectrum of water.

"A radiation wavelength that is significantly absorbed by water vapor" means a radiation wavelength that water vapor absorbs to a degree that can be sensed and distinguished as characteristic of water vapor. The wavelength significantly absorbed by water vapor is preferred to be at or near the center of a peak or 15 maximum wavelength range in the absorption spectrum of water.

"A radiation wavelength that is not significantly absorbed by water vapor" at or near the center of a valley or minima in the absorption spectrum of water.

"A radiation wavelength that is significantly absorbed by the material composing the structure" means a radiation wavelength at or near the center of a 20 valley or minimum wavelength range in the absorption spectrum of such material.

"Detection wavelength" means the wavelength at which sensing of the radiation from the structure is performed, and is either the same wavelength as the exposure wavelength or the emission wavelength.

"Emission wavelength" means a wavelength at which radiation is emitted as 25 a result of absorption of energy at the exposure wavelength in a substance such as water, water vapor, a water-soluble substance, or fungi.

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"Exposure wavelength" means an electromagnetic radiation wavelength absorbed by a substance such as water, water vapor, a water-soluble substance, or fungi. "Reference wavelength" is a wavelength that is not significantly absorbed by 5 a substance such as water, water vapor, a water-soluble substance, or fungi if the detection wavelength is one at which the degree of absorption is to be determined. If the detection wavelength is an emission wavelength, the reference wavelength is one at which no significant emission occurs from the substance under analysis upon exposure to radiation at the exposure wavelength, and that is also not significantly 10 absorbed by the material composing the structure.

"Material" as used herein refers to construction materials such as wood, brick, stone, drywall or sheet rock, panels of vinyl or stucco, or other materials used in the construction of a structure such as a building or house.

"Substance" as used herein can be either water, water vapor, a watersoluble 15 substance, or fungi.

Water" as used herein means water in its liquid phase unless the context used herein indicates its use in a general sense, in other words, water whether in liquid, gas, or solid form.

"Water vapor" refers to water in its liquid phase.

I. A System for Use in Performing the Methods In Fig. 1, a system 10 that can be used to perform the invented methods, is shown. The system 10 generally includes an electromagnetic radiation generator 12 and a sensor unit 14 used to determine whether a water-suspect area exists in an 25 predetermined area of the structure]6, and/or to determine the presence of a water-soluble substance and/or fungi. The structure 16 can be a house, building or other structure. The electromagnetic radiation generator 12 generates electromagnetic radiation 18 that includes at least one exposure wavelength(s) that is significantly absorbed by the substance that is to be detected (i.e., water, -8

water-vapor, water-soluble substance or fungi) and at least one reference wavelength that is not significantly absorbed by such substance. The exposure and reference wavelengths are predetermined to be wavelengths that are not significantly absorbed by the material composing the structure 16. The generator 12 can generate the 5 exposure and reference wavelengths in a range from 10-2 microns to 108 microns, for example, although other appropriate wavelengths can be used. The exposure and reference wavelengths of the radiation generated by the generator 12 can be at wavelengths in the ultraviolet (UV), visible (VIS), infrared (JR) andlor radio-wave range. The exposure and reference wavelengths are preferred to be wavelengths that 10 penetrate relatively deeply into the structure material so that areas of the structure hidden from view by the unaided eye can be analyzed for the presence of a particular substance to be detected. The generator 12 can be a unit that generates a relatively broad spectrum of wavelengths. For example, the generator 12 can be a lamp in the form of a light bulb (e.g., a quartz halogen-type lamp) that optionally includes a 15 reflector to intensify and direct the radiation generated by the lamp in a predetermined direction. The lamp and reflector are commercially-available from various suppliers of the sensing unit 14, or from a wide variety of other commercial sources. The generator 12 can also be a unit that generates electromagnetic radiation at relatively specific wavelengths, such as a laser. For some exposure and reference 20 wavelengths, it may not be possible to select a commercially-available laser or to construct such laser to inherently operate exactly at such wavelengths. In this case, the laser can include tunable elements to permit adjustment of the wavelength of the radiant energy generated by the laser to coincide or nearly coincide with the exposure and reference wavelengths. Alternatively, a laser can be selected from 25 commercially-available units or can be constructed to generate a wavelength sufficiently close to the exposure wavelength to permit absorption of radiant energy at the exposure wavelength if water is present in the structure. Similarly, a laser can be selected from commercially-available units or can be constructed to generate a wavelength sufficiently close to the reference wavelength so that it is not 30 significantly absorbed by water if present in the structure. Many commercially-available lasers include a calibration sensor that can be used to adjust

the wavelength of the electromagnetic radiation generated by such lasers. Because lasers generally generate radiation with a relatively narrow beam width, a beam expander or pin-hole or slit grating (not shown) can be used to enhance a laser's beam width to expose a relatively large area of the structure 16. The generator 12 5 can also include a source of radiowaves. To simplify determination of the area of the structure that is exposed with the generator 12, the generator 12 can generate electromagnetic radiation in the VIS range as part of the exposure wavelength or in addition to the exposure wavelength to permit a human user to see the exposed area of the structure. Alternatively, the generator 12 can be provided with a view finder 10 similar to those commonly used in cameras to permit the exposed area of the structure to be determined. The system 10 can include a photographer's stand 20 of a type commonly used and commercially-available for videotaping in the television industry, or a tripod, for example. One or more lamps or lasers of the generator 12 can be installed in and supported by the stand 20. The intensity of the radiation 15 generated by the generator 12 should of course be sufficient to permit detection of the presence of water, a water-soluble substance and/or fungi in the structure 16, but must not be so intense as to significantly evaporate water present in the exposed area of the structure, an occurrence which could disguise a water problem. In general, the output power of the generator 12 can be in a range from ten (10) to one-thousand 20 (1,000) Watts. The stand can be positioned at a location in contact with the structure to a location that is as much as about five to ten meters from the area of the structure under analysis. In general, the closer the generator 12 is positioned to the structure, the less the intensity required for the radiation output by the generator. Conversely, in general, the farther the generator 12 is positioned from the structure 16, the 25 greater the intensity required for the radiation 18 generated by the generator 12. If the system 10 is to detect radiant energy reflected from the structure, the generator 12 can be positioned at an angle of thirty (30) degrees of angle relative to a wall surface, for example, so that the electromagnetic radiation *om the generated glances from the structure. The generator 12 can be powered by electrically coupling 30 the generator to an electrical wall outlet (not shown) of the structure with an -10

extension cord or wiring (not shown), or can be powered by electrically coupling the generator to a portable electrical power generator or battery (not shown).

The generator 12 is positioned on the stand 20 to expose a predetermined area of the structure 16 to the radiation 18 that is generated by the generator at 5 exposure and reference wavelengths. In Fig. 1, the sensor unit 14 is positioned to receive and sense electromagnetic radiation 22 from the structure 16, the radiation 22 being derived from the radiation 18. The sensor unit 20 can detect the intensity of the radiation 22 at a detection wavelength. The detection wavelength can be the same as the exposure wavelength if the degree of absorption of the exposure 10 wavelength is to be used to detect the presence of a substance (i.e., water, water vapor, water-soluble substance or fungi). In this case, the radiation 22 can be a portion of the electromagnetic radiation l 8 that is not absorbed in the structure 16 and that is reflected from the structure 16, as shown in Fig. 1. The detection wavelength can also be an emission wavelength of water that is excited by the 15 exposure wavelength in the radiation 18. The emission wavelength is generally different from the exposure wavelength. If the substance to be detected is present in the structure, the water molecules absorb the radiation at the exposure wavelength and emit energy received in the exposure wavelength at an emission wavelength that can be sensed by the sensor unit 14 via the radiation 22 to determine whether a the 20 substance is present or suspected to be present in the exposed area of the structure 16. The sensor unit 14 can also sense the radiation 22 received by the sensor unit at the reference wavelength whose intensity is proportional to that of the radiation 18 if the degree of absorption is to be detected at the detection wavelength, or can be a wavelength at which significant emission does not occur if the detection wavelength 25 is an emission wavelength. Accordingly, the reference wavelength serves as a measure of the radiation 18 incident to the structure 16 against which the intensity of the radiation 22 at the detection wavelength can be gauged.

The sensor unit 14 can include conditioning element(s) 24 and sensor(s) 26 which are arranged to receive radiation 22 from the conditioning element(s). The 30 conditioning element(s) 24 can include one or more filters or gratings to receive and -1 1

pass the detection and reference wavelengths in the radiation 22, but which reject other wavelengths. The conditioning element(s) 24 can also include a prism or like element to separate received radiation 22 into different wavelengths for supply to different sensors 26 sensitive to different wavelength ranges, for example. The 5 conditioning element(s) 24 can also include one or more lenses to focus light on the sensors 26, or can include one or more mirrors to guide the radiation 22 along an optical path traveled by such radiation to the sensor(s) 26.

The sensor(s) 26 can generate at least one signal, based on the intensity level(s) of the radiation 22 at the detection wavelength(s), and at least one signal 10 based on the intensity level(s) of the radiation 22 at the reference wavelength(s). The sensor(s) 26 can include one or more photodiodes arranged in an array, a charge-coupled device (CCD), and/or a charge-injected device (CID). The sensor(s) 26 can also include various sensors used in radiometers to sense radiowaves. If the sensor(s) 26 is sensitive to a relatively narrow band of wavelengths, such sensor(s) 15 should be selected from among commercially-available sensor(s) or constructed to be sensitive to the exposure and reference wavelengths. The sensor(s) 26 can also include tunable or wavelength-adjustment elements to adjust such sensor(s) to be sensitive to the exposure and reference wavelengths. The sensor(s) 26 can detect the radiation 22 over a relatively large field of view of the exposed predetermined area

20 of the structure 16, for example, of about a square meter to several square meters or more. This permits a relatively large area of the structure to be analyzed for the presence of a substance in a single exposure so that comparatively less repositioning of the generator 12 and the sensor unit 14 is required to scan a portion of the structure for the presence of a particular substance. The sensor unit 14 can include a 25 processor 28 coupled to receive the signals from the sensor(s) 26. The processor 28 can be a microprocessor or microcontroller, for example. The sensor unit 14 can also include an analog-to-digital converter (not shown) coupled between the sensor(s) 26 and the processor 28, to convert the signals from the sensor(s) 26 from analog signals into digital data. The sensor unit 14 can also include a memory 30 coupled to 30 the processor 28, that can receive and store data representing the detection and reference wavelength intensity level data for the radiation 22, as weld as a control -12

program pre-stored in the memory 30 that controls the operations of the processor 28, and data signals generated by the processor 28 based on the intensity level data.

The processor 28 can be pre-prograrntned to compare the intensities of the detection and reference data levels. If the detection and reference levels differ by a 5 predetermined amount stored in the memory 30, the processor 28 can generate a data signal to indicate that a particular substance is present, or is suspected to be present, in the predetermined area of the structure exposed by the generator 20. Conversely, if the processor 28 determines that the detection and reference level data do not differ by the predetermined amount data, the processor 28 can generate a signal to I O indicate that no such substarce is present in the exposed predetermined area of the structure. The predetermined amount data is determined based on the absorption or emission spectra at the detection and reference wavelengths, and serves as a threshold level against which the difference of the detection and reference wavelength intensity level data can be gauged to determine whether the substance is 15 present in the exposed area of the structure 16. The amount data is predetermined based on the relative difference of the absorption or emission spectrum of the absorption or emission phenomenon to which the detection and reference wavelengths are related. Such amount data can also be predetermined to account for the capability of the generator 12 to generate the radiation 18 at the detection and 20 reference wavelengths, the sensitivity and wavelength resolution capability of the sensor unit 14 at the detection and reference wavelengths, and other factors well-known to those of ordinary skill in this technology. The sensor(s) 26 can be such as to generate signals based on the radiation 22 that are arrays of pixel data representing images of the exposed area of the structure at the detectionand 25 reference wavelengths. The processor 28 can be pre-prograrmned to receive the arrays of pixel data from the sensor(s) 26, and to repeatedly perform comparisons of the detection and reference data levels for corresponding pixels of the arrays generated by the sensor(s) 26 at the detection and reference wavelengths. The processor 28 can generate signal(s) or image data that is an array of pixel data 30 indicative of whether a particular substance (e.g., water, water vapor, a water-soluble substance or fungi) is present in the structure at each pixel of such array. The -13

processor 28 can also store the generated image data in the memory 30 for later retrieval. In addition, the processor 28 can repeatedly perform for comparisons of a plurality of different detection and reference wavelengths to generate signals or image data that indicate whether the substance exists for the pixel data of the arrays 5 resulting from such comparisons. The sensing unit] 4 can include a display unit 32 that is coupled to the processor 28. The processor 28 can use the image data it generates to produce a display that indicates areas in which the substance is suspected or determined to be present by the processor 28, and those areas in which the substance is not suspected or determined to be present. The display permits a 10 human user to readily ascertain where a particular substance is or is not present in the exposed area of the structure 16. For example, the human user can use the display as an aid to determine the source of a water problem in the structure 16.

The sensor unit 14 can be one of a variety of commercially available units that includes the sensor(s) 26, but which may or may not include the remaining 15 elements of the sensor unit 14 of Fig. 1, depending upon the particular unit. Such corrnercially available units include a hyperspectral imaging system from Opto-Knowledge Systems, Inc. of Torrance, California, auld model no. A109000 sold under the trademark FieldSpec FR from Analytical Spectral Devices, Inc.,

Boulder, Colorado. The hyperspectral system is capable of sensing at a plurality of 20 different detection wavelengths. The hyperspectral imaging system is sold as in a package that includes the generator 12. For the model no. A109000, the generator 12 can be a "high intensity lamp assembly," model. no. A126530, commercially available from Analytical Spectral Devices, Inc. The above-listed units generally operate in or near the IR, VIS and UV wavelength ranges. A unit that operates in the 25 radio-wave region is the GZ5 microwave sensing system commercially available from Geozondas, Corporation of Lithuania. Such unit incorporates both the generator 12 and the sensor unit 14. [he sensor unit 14 can be supported by a stand 35 such as a tripod, photographer's stand, or other device commercially available from a variety of commercial sources, including suppliers of the generator 12 and/or 30 the sensor unit 14. A user can position the sensor unit 14 on the stand 35 using a view finder mounted to the sensor unit and aligned with the sensor unit's -14

field-of-view. Using the view finder, the user can position the sensor unit 14 to

receive electromagnetic radiation 22 from the structure 16 from the area exposed with radiation 18 by the generator 12. Positioning of the sensor unit 14 is simplified to a degree if the generator 12 generates the radiation 18 so that it includes at least 5 some wavelengths in the VIS range so that the user can more readily position the sensor unit 14 on its stand 35 to receive radiation 22 that results from the area of the structure exposed by radiation 18. If the system 10 is to be used to detect electromagnetic radiation reflected from the structure 16, the sensor(s) 26 can be aligned to oppose the generator 12 and about thirty (30) degrees of angle, for 10 example, with respect to the structure's surface to receive electrorr.agnetic radiation from the generator.

The sensor unit 14 can include an external data interface 34 electrically coupled to the processor 28. The external interface 34 can be coupled to supply data from the sensing unit 14, or more specifically, the memory 30 via processor 28, to a 15 computer 36 of the system 10, that is external to the sensing unit 14. The computer 36 can be a personal computer (PC) such as a unit including a microprocessor or microcontroller, such as a Pentium's II or III microprocessor-based unit. In response to command data input by a user via the computer 36 to the processor 28, the processor 28 can be pre-programmed to output data from the memory 30 to the 20 computer 36 via the interface 34. The data output by the processor 28 can include image data indicating water-suspect areas and/or dry areas of the structure, or areas data in which a water-soluble substance or fungi are determined to be present by the sensor unit 14 and those areas where such substance is not present. Alternatively, the data output from the memory 30 via the processor 28 to the computer 36 through the 25 interface 34 can also include intensity level data for the detection and reference wavelengths, optionally in the form of arrays of pixel data, in which case the computer 36 can he prc-prograron1ed to determine areas in which the substance under analysis is present and not present in the exposed area of the structure 16, based on the intensity level data. The computer 3 6 can generate a display on the 30 display unit 3 8 to permit a human user to view the image data of the exposed area of the structure, indicating those areas in which a particular substance is present or is -

not present, based on the intensity level data, in a manner similar to that previously described with respect to the processor 28. The interface 34 is preferred to be detachable (e.g., a cable connection between the processor and computer that can be unplugged) so that the sensor unit 14 and the computer 36 can be disconnected from 5 one another. 'The use of the interface 34 permits intensity level data to be gathered and stored in the sensor unit 14 in an, on-site inspection of the structure 16, which can then be carried off-site to a remote office, for example, to download the intensity level data into the computer 36 for analysis of the presence of a particular substance in the structure 16. The printer 40 is coupled to the computer 36, and can be used to 10 print the image data indicating areas in which the substance to be detected in the structure is present, and predetermined areas where such substance is not present, for inclusion in a report to the property owner, for example.

In Fig. 2, the system 10 is shown in a different arrangement as compared to Fig. 1. More specifically, the generator 12 and the sensing unit 14 are positioned on 15 opposite sides of the predetermined area of the structure 16 to be exposed for analysis. For example, the generator 12 and the sensing unit 14 can be positioned on opposite sides of a wall, floor, ceiling or roof of the structure 16, for example. The generator 12 can be positioned via stand 20 to generate electromagnetic radiation traveling in a direction at least approximately perpendicular to the structure's 20 surface. The sensing unit 14 is positioned to oppose the generator 12 on the opposite side of the structure so that the sensor(s) 26 receive electromagnetic radiation traveling through the structure in a direction at least approximately perpendicular to the structure's surface.

II General Disclosure of the Method for Detecting Presence (or Absence)

c 25 Of A Substance In A Structure With reference to Fig. 3, the general method of the present invention is now described. The method begins in step Sl. In step S2, the structure is exposed to electromagnetic radiation including at least one wavelength significantly absorbed by a predetermined substance. The substance can be water, a water-soluble 30 substance such as carbonate, phosphate, sulfate, or chloride minerals, or fungi that -16

grows in the presence of water. In step S3, electromagnetic radiation is sensed from the structure. The sensed radiation is based on the radiation used to expose the structure, and can be, for example, the unabsorbed portion of the exposed radiation reflected from or transmitted through the structure, or can alternatively be radiation 5 emitted by the substance due to excitation by the radiation used to expose the structure. In step S4, a determination is made to establish whether the sensed radiation indicates that the substance is present in the structure. If the result of the determination of Fig. 3 is affimnative, in step S5, the substance is determined to be present in the structure. On the other, if the determination in step S4 is negative, in 10 step S6, the substance is determined not to be present in the structure. After performance of either steps S5 or S6, the method ends in step S7.

Absorption or emission spectra shift to a degree depending upon the temperature of the substance under analysis. Therefore, it is preferred that the method of Fig. 3, as well as all other methods described herein, be performed at l 5 about room temperature (approximately 20' Q. Care should be taken when performing the method on sunny days or in structures with significant amounts of glass because sun light can heat structures to relatively high temperatures which could adversely affect performance of the disclosed methods.

III. General Disclosure of the Method for Detecting Presence (or Absence) of Water

20 in a Structure With reference to Fig. 4, the general method of the present invention is now described. The method begins in step Sl. In step S2, the generator 12 is positioned to expose a predetermined area of the structure 16 to be analyzed for the presence of water with radiation 18. In step S3, the sensor unit 14 is positioned to receive and 25 sense radiation 22 from the structure 16. In step S4, the generator 12 generates electromagnetic radiation 18 which includes at least one exposure wavelength that is significantly absorbed by water. In step S5, the structure is exposed with the generated radiation 18. In step S6, the sensor unit 14 receives the radiation 22 from the structure 16, the received radiation based upon or derived from the radiation 18 30 used to expose the predetermined area of the structure. In step S7, the sensor unit 14 -17

senses the received radiation 22. In step S8, a determination is made to establish whether the exposed area of the structure 16 unit includes a water-suspect area. If the determination in step S8 is affimnative, in step S9, testing is performed to confirm the presence of water in the water-suspect area of the structure. In step S10, a 5 determination is made to establish whether which the water-suspect area does in fact include water. If the determination in step S 10 is affirmative, in step S 11, the source of the water in the water-confimned area is determined. After the source of the water problem is determined in step Sl 1 or if the determinations in steps S8 or S10 are negative, in step S12, the method ends. Steps S8 - S12 can be performed either by 10 the processor 28, the computer 27 or a human user of the rr ethod of Fig. 4.

IV. Relatively Specific Embodiment of the Method for Determining the Presence (or Absence) of a Water-Suspect Area of a Structure A relatively specific embodiment of the method for determining whether water is present in a structure begins in step S 1 of Fig. SA. In step S2, at least one 15 exposure wavelength is determined to be one that is significantly absorbed by water and not significantly absorbed by the material composing the structure. By way of example and not limitation, the exposure wavelengths can include at least one wavelength at about 0. 76, 0.97, 1.19, 1.45, 1.94, 2.55, 2.7, 5.5 and 10.7 microns, which are significantly absorbed by water and are generally not significantly 20 absorbed in materials used in structures (for graphs of absorption spectra, see pg.

1957, FT-NIR Atlas, M. Buback and Il.P. Vogele, ISBN 3-527-28567-9, VCH Publishers, New York, NY; interact at www.asdi.com). To determine a wavelength that is not significantly absorbed by the material composing the structure, the material composing the structure can be tested with a spectrometer, for example, to 25 determine the absorption spectra of the material at wavelength ranges under consideration for use as the exposure wavelength. By analyzing the material's absorption spectra, an exposure wavelength that is not significantly absorbed by the material can be readily determined. Optionally, the exposure wavelength can be a wavelength that excites emission at an emission wavelength of water. In step S3, a 30 reference wavelength is detennined as a wavelength that is not significantly absorbed by water and is also not significantly absorbed by the material composing -18

the structure. Detennination that the reference wavelength is not significantly absorbed by the structure can be performed by using a spectrometer in a manner similar to that used to determine the exposure wavelength. Alternatively, if the detection wavelength is an emission wavelength, the reference wavelength should be 5 one at which no significant emission from water occurs, and which also is not significantly absorbed by the material composing the structure. For example, the reference wavelength can include at least one wavelength at about 1.06 and 1.66 microns, which wavelengths are not significantly absorbed by water. In step S4, a detection wavelength(s) is determined to be one that is sensitive to the exposure l 0 wavelength(s) in the presence of water, and that is not significantly absorbed by the material composing the structure. The detection wavelength can be the same wavelength as the exposure wavelength if absorption is to be used to determine the presence of a water-suspect area, or can be an emission wavelength of water that is excited by the exposure wavelength. Such emission wavelength could include about 15 3.2 or 6.2 microns, for example, in which case the exposure wavelength should be at least one wavelength that is significantly absorbed by water and that is a shorter wavelength than about 3.2 or 6.2 microns to ensure that sufficient excitation energy is provided to any water molecules present to excite emission at such wavelengths.

In step S5, the generator 12 is positioned to expose a predetermined area of the 20 structure 16 with the radiation 18 at the exposure and reference wavelengths. Such step can be performed by a human user of the method using the stand 20 that supports the generator 12 and/or a view finder or visible radiation 18 generated by the generator 12, which reveals the area of the structure exposed by the radiation 18.

The area of the structure 16 to be exposed by the radiation 18 can be marked with 25 removable chalk or ink, for example, for use in positioning the sensor unit 14. In step S6, the sensor unit 14 is positioned to receive auld sense electromagnetic radiation 22 from the predetermined area of the structure 16 to be exposed with the radiation 18. Step S6 can be perfonned by a human user of the method using the stand 35, optionally with a view finder to align the sensor unit 14 to receive the 30 electromagnetic radiation 18 from the area of the structure exposed by the generator 12. Positioning of the sensor unit 14 can be facilitated if the generator 12 generates -19

radiation 18 to include visible wavelengths, or the area to be exposed by the radiation 18 can be delineated with a marker to permit the user to position the sensor unit 14 to receive radiation 22 from the structure area exposed by radiation 18. In step S7' the generator 12 generates the electromagnetic radiation 18 including the 5 determined exposure and reference wavelengths. In step S8, the generator 12 exposes the predetermined area of the structure l 6 to be analyzed for the presence of a water-suspect area, with the radiation 18 which includes the exposure and reference wavelengths. In step S9, the sensor unit 14 receives the radiation 22 from the exposed predetermined area of the structure 16. The received radiation 22 is 1G based upon (or in other words derived from) the radiation 18 used to expose the structure 15. In step S 10, the sensor unit 14 senses an intensity leve! of the radiation 22 at the detection wavelength determined in step S4. The sensor unit 14 also senses an intensity level of the reference wavelength determined in step S4 from the radiation 22. In step S11 of Fig. 513, the intensity levels of the exposure and 15 reference wavelengths are compared. In step S12, a determination is performed to establish whether the intensity levels of the detection and reference wavelengths differ by a predetermined amount. Preferably, the predetermined amount is at least ten percent (10%) of the reference wavelength's intensity, although this need not necessarily be so as long as the sensor(s) 26 are sufficiently sensitive to distinguish 20 the detection and reference wavelengths' intensity levels if water is present in the exposed area of the structure. If the detection and reference wavelengths differ by the predetermined amount as determined by the performance of step S 12, the method proceeds to step S13 in which a water-suspect area is determined to exist in the structure. In step S14 of Fig. 5B, testing is performed to determine whether the 25 water-suspect area includes water, or is due to some other cause such as missing insulation or the presence of different structural materials, for example. The presence of water in tile water-suspect area in step S14 can be performed by the method of Figs. 6A and 613 which will be described in detail later in this document.

Alternatively, the testing to confirm the presence of water in the watcrsuspect area 30 can also be performed with a moisture detector such as the model KJE-100 from Zeltex, Inc., Hagerstown, Maryland. The testing to confirm the presence of water in -20

step S14 can also be performed in numerous other ways, such as those set forth in U.S. Patent No. 5,886,636 issued March 23, 1999 to Patrick J. Toomey, the subject inventor. For example, the water-suspect area can be confirmed as containing water by scanning the water-suspect area with a capacitance meter, and determining 5 whether the water-suspect area includes water, based on the reading of the capacitance meter. Alternatively, the water-suspect area can be confirmed as containing water by positioning an endoscopic probe in the structure in proximity to the water-suspect area, viewing the water-suspect area with the endoscopic probe, and determining whether the water-suspect area includes water, based on the 10 viewing of the water-suspect area. As another alternative, the water-suspect area can be confinned as including water using spaced conductive pins electrically coupled to a resistively meter. The pins are inserted or driven into the water-suspect area of the structure, and a signal is applied to one of the pins. The resistively meter senses the signal level on at least one other pin, and a determination is made to establish 15 whether the water-suspect area of the structure is due to the presence of water, based on the signal level sensed by the resistively meter. Because the presence of water generally enhances electrical conductivity in the structure's materials, the less resistance observed between the pins, the more likely water is present, and vice versa. In step S15 of Fig. 513, a determination is made to establish whether the 20 water-suspect area in fact includes water, based on the testing performed in step S 14.

If the determination in step S15 is affirmative, the source of the water is determined in step S16. Step S16 can be performed in numerous ways, including those disclosed in U.S. Patent No. 5,886,636. More specifically, the source of the water can be detemmined by detecting pH of water from the water-confirmed area with a litmus 25 paper or pH meter, determining the source of the water to be rain if the detected pH is relatively acidic, and determining that the source of the water is not rain if the water is not relatively acidic. Alternatively, the source of the water in the water-confimled area of the structure 16 can be determined by sensing the salinity of water from the water-confirmed area with a salinity meter, for example, determining 30 that the water-confimned area is due to ground water if the water is relatively saline, and determining that the water-confimned area is not due to ground water if the -21

water is not relatively saline. As another altemative, the generator 12 and the sensor unit 14 can be used, for example, in the performance of the method set forth later in this document with reference to Figs. 7, 8A and 8B to determine whether the source of the water in the water- confimned area of the structure is ground water. After 5 performance of step S16, or if the determination of either of steps S12 of S1S are negative, the method of Figs. SA and 5B ends in step Sl7. Steps S1 - S13 can be performed either by the processor 28, the computer 3 6 or a human user of the method of Figs. SA and 5B. Steps S 14 -S 17 of Figs. 5A and SB can be performed by a human user of the method using appropriate equipment and techniques such as 10 those previously described.

In general, the method of Figs. SA and SB accomplishes detection of water in an exposed area that is a portion of a wall, floor, ceiling or roof of a structure, for example. Therefore, the method of Figs. SA and SB can be repeated to scan a relatively large part of a structure. To track where water detection using the method 15 has been performed, a marker such as tape, or chalk or removable ink can be used to mark those areas where the method has been applied and those areas yet to be scanned. V. Relativel S ecific Embodiment of the Invented Method using Y P Exposure Wavelengths of Both Water and Water Vapor 20 In Fig. 6A, a method for detecting a water-suspect area in a structure that uses exposure wavelengths for both water and water vapor, begins in step S 1. In step S2, a water exposure wavelength for the radiation 18 is determined to be used to expose a predetermined area of a structure 16. The water exposure wavelength is determined to be a wavelength that is significantly absorbed by water and is not 25 significantly absorbed by either water vapor or the material composing the structure lG. In step S3, at least one reference wavelength for water is determined that is not significantly absorbed by water, water vapor or the material composing the structure.

In step S4, a water detection wavelength is determined. The water detection wavelength is determined to be sensitive to the water exposure wavelength if water 30 is present in the exposed area of the structure 16, and is not sensitive if water is -22

absent from the exposed area of the structure 16. The detection and exposure wavelengths for water can be the same wavelength. or the detection wavelength for water can be an emission wavelength at which emission occurs from water as a result of absorption at the water exposure wavelength. In step S5, an exposure 5 wavelength for water vapor is determined, such wavelength being significantly absorbed by water 16 vapor but not significantly absorbed by either water or the material composing the structure 16 or the material composing the structure. In step S6, a reference wavelength(s) for water vapor is determined. The reference wavelength is one that is not significantly absorbed by water vapor or water, and that l0 is also not significantly absorbed by the material composing the structure 16.

Optionally, the reference wavelength can be one at which no emission from water occurs if the water detection wavelength is an emission wavelength of water that is excited by the water exposure wavelength. In step S7, a detection wavelength for water vapor is determined that is sensitive to the exposure wavelength for water 15 vapor, and that is not significantly absorbed by either water or the material composing the structure 16. Importantly, in steps S2 and S5, the exposure wavelengths that are significantly absorbed by water and water vapor can be determined to be wavelengths that are related to one another (i.e., wavelengths related to the same molecular absorption mechanics such as a particular mode of 20 molecular vibration), but that are shifted in wavelength by the transition of water between the liquid and vapor phases. Such exposure wavelengths can be used as highly effective indicators of the presence of water in a structure. Exemplary exposure wavelengths significantly absorbed by water and water vapor that exhibit this wavelength shift upon phase transition between water and water vapor include 25 about 0.97 microns and 0.935 microns, 1.2 microns and 1.13 microns, 1.45 microns and] .38 microns, told 1.94 microns and 1.86 microns, where the exposure wavelength pairs represent the wavelengths of significant absorption for water and water vapor, respectively. 'l'he reference wavelengths for water and water vapor determined in steps S3 and S6 can be the same wavelength at about 1.06 microns 30 and 1.66 microns (neither of these wavelengths is significantly absorbed by either water, water vapor or many types of structure construction materials), although the

reference wavelengths for water and water vapor need not be the same wavelength.

Alternatively, if the water vapor detection wavelength is an emission wavelength, the water vapor reference wavelength is determined to be one at which no significant emission occurs from water exposed to the radiation 18 in addition to such wavelength not being significantly absorbed by either water or the material composing the structure 16. In step S8 of Fig. 6A, the generator 12 is positioned to expose a predetermined area of the structure 16 to the electromagnetic radiation 18.

If the generator 12 produces visible wavelengths, the exposed area of the structure 16 can be readily determined and the generator 12 positioned by a human user of the 10 method with the stand 20 to expose a predetermined area of the structure.

Optionally, step S8 could also be performed with a view finder mounted to the generator 12 which indicates the area of exposure of the radiation 18 generated by the generator 12, and such area can be marked with chalk, ink or other removable substance for use in positioning the sensor unit 14. The generator 12 can be 15 positioned to expose a border between a water-suspect area and a relatively dry predetermined area of the structure 16 where the structure may be drying after the occurrence of a water problem, for example. At a border between a water-suspect area and a relatively dry predetermined area of the structure, both water and water vapor are usually present in significant and detectable concentrations. In step S9, the 20 sensor unit 14 is positioned to receive the electromagnetic radiation 22 that is based on the radiation 18, from the predetermined area of the structure 16 that is to be exposed. The sensor unit 14 can be positioned by a human user of the method using stand 35 and a view-finder mounted to the sensor unit 14, which indicates the field-of-view over which the sensor unit 14 receives the radiation 22 from the area of

25 the structure 16 exposed by the radiation 18. Optionally, the sensor unit 14 can be positioned through the use of visible wavelengths included in the radiation 18 generated by the generator 12, which indicate the area of the structure 16 that is to be exposed. Alternatively, the sensor unit 14 can be positioned to receive the radiation 22 from the area of the structure 16 that is to be exposed with the radiation 18 using 30 chalk or ink markings on the structure 16 made by using a view finder of the generator 12 that indicates the area of the structure that will be exposed by the -24

radiation 18. In step S10 of Fig. S13, the generator 12 generates the electromagnetic radiation 18 that includes the determined exposure and reference wavelengths for both water and water vapor. In step S 11, the generator 12 exposes the predetermined area of the structure 16 with the generated electromagnetic radiation 18. In step S12, 5 the sensor unit 14receives the radiation 22 from the exposed predetermined area of the structure 16 at the detection and reference wavelengths for both water and water vapor. In step S13, the sensor unit 14 senses the electromagnetic radiation 22 to determine radiation intensity levels for the detection and reference wavelengths for both water and water vapor. In step S14, the intensity levels of the water detection 10 and reference wavelengths are compared. In step SlS, a determination is made to establish whether the intensity levels of the water detection and reference wavelengths differ by a predetermined amount. If the determination in step S15 is affirmative, in step S16, the radiation intensities of the water vapor detection and reference wavelengths are compared. In step S17, a determination is made to 15 establish whether the intensity levels for the detection and reference wavelengths for water vapor differ by a predetermined amount. If the determination of step S17 is affirmative, in step S 18, a determination is made that water is present in the exposed area of the structure 16. If the determinations of steps S15 or S17 are negative, in step S19, water is determined not to be present in the exposed area of the structure 20 16. After performance of steps S18 or S19, the method of Figs. 6A and 6B ends in step S20. Steps S14 - S20 can be performed by either the processor 28 of the sensor unit 14, the computer 36 or a human user of the method.

Vl. A Method for Detectin the Presence (or Absence) of a Water-Soluble Substance g Indicative of the Presence o f Ground Water in Structure 25 In Fig. 7, a method for detecting the presence of a water-soluble substance in a structure begins in step S1. In step S2, the generator 12 is positioned to expose a predetermined area of a structure l 6 with the radiation l 8. In step S3, the sensor unit 14 is positioned to receive and sense electromagnetic radiation 22 from the predetermined area of the structure 16 to be exposed by the radiation 18. In step S4, 30 the generator 12 generates the electromagnetic radiation 18 that includes at least one exposure wavelength that is significantly absorbed by a watersoluble substance -25

commonly present in earth. Such water-soluble substances include carbonates, chlorides, fluorides, sulfates and other minerals. Such watersoluble substances, if present in a structure, are generally highly indicative that the source of a water problem is ground water. In step S5, the generator 12 exposes the predetermined 5 area of the structure with electromagnetic radiation 18 including the wavelength significantly absorbed by the water-soluble substance. In step S6, electromagnetic radiation 22 based on the radiation 18, is received by the sensor twit 14 from the exposed area of the structure 18. In step S7, the received radiation 22 is sensed by the sensor unit 14. In step S8, a determination is made to establish whether the 10 water-soluble substance is present in the exposed area of the structure 16. If the result of the determination in step S8 is affirmative, ire step S9, the source of water in the structure 16 is determined to be ground water. On the other hand, if the result of the determination of step S8 is negative, in step S10, the water source is determined not to be ground water. After performance of either steps S9 or S10, the method of 15 Fig. 7 ends in step S 1 1.

VII. A Relatively Specific Embodiment of the Method for Detecting the Presence (or Absence) of a Water-Soluble Substance indicative of the Presence of Ground Water in a Structure A relatively specific embodiment of the method for detecting the presence of 20 a water-soluble substance in a structure 16 begins in step Sl of Fig. 8A. In step S2, exposure wavelength(s) for the electromagnetic radiation 18 is determined as one that is significantly absorbed by one or more water-soluble substances common in ground water, and that is not significantly absorbed either in water or the material composing the structure 16. The water-soluble substance can include at least one of 25 gypsum (CaSO41I2O), anhydrite (CaS04), apatite (Ca5(PO4)4(0H,F,CI)), halite (NaCI), sylvite (KCI), calcite (CaC03), magnesite (MgC03), magnesium-iron (Mg-l e) solid solution, siderite (FeC03), rhodocrosite (MnC03), smithsonite (ZnC03), dolomite (CaMg(C03)2) and kutnahorite (Ca(Mn, Mg,}e)(C03)2), which generally have similar absorption spectra in the NIR and IR range. The exposure wavelength that is 30 significantly absorbed by the watersoluble substance can include at least one wavelength of about 6.6 8.7, 9. 6, 1 l.5, and 14 microns, for example (see internet, -26

http://emma.la.asu.edu for graphs of absorption spectra). The exposure wavelength can also be one that excites emission from the water-soluble substance if present in the exposed area of the structure 16 at an emission wavelength, and should be a wavelength that is neither absorbed by water nor the material composing the 5 structure 16. Care should be utilized in the determination of the exposure wavelength because some structure materials, particularly drywall and cements, can include gypsum as a constituent. In step S3, a reference wavelength(s) is determined for the electromagnetic radiation 18 that is not significantly absorbed by the water-soluble substance, water, and the material composing the structure 16. The 10 reference wavelength that is not significantly absorbed by water-soluble substances, water, and many structure materials includes wavelengths from 7.5 to 8.Q microns.

Alternatively, if the detection wavelength is an emission wavelength of the water-soluble substance, the reference wavelength(s) should be one at which no significant emission occurs and which is not significantly absorbed by water and the 15 material composing the structure 16. In step S4, a detection wavelength is determined for the electromagnetic radiation 22 to be received from the exposed area of the structure. The detection wavelength(s) is one that is sensitive to the exposure wavelength in the presence of the water-soluble substance, but that is not significantly absorbed by water and the material composing the structure 16. In step 20 S5, the electromagnetic generator 12 is positioned to expose a predetermined area of the structure 16 to be analyzed for the presence of the water-soluble substance. Step S5 can be performed by a human user of the method using the stand 20. Optionally, the generator 12 generates radiation 18 to include visible wavelengths which can be used to determine the area of the structure 16 that will be exposed by the radiation 25 18. Alternatively, the generator 12 can include a view finder to indicate the area of the structure 16 that will be exposed by the radiation 18. In step S6, the sensor unit 17 is positioned to receive Ad sense electromagnetic radiation front the structure area to be exposed with radiation 18. Step S6 can be performed by a human user of the method using the stand 35. Positioning of the sensor unit 14 is facilitated if the 30 generator 12 can generate the radiation 18 to include visible wavelengths indicating the exposed area of the structure 16. Alternatively, the area of the structure 16 that -27

will be exposed by the radiation of the generator 12 can be marked with chalk, ink or other removable substance so that the sensor unit 14 can be aligned to such marking using a view finder. The sensor unit 14 can include a view finder to assist the user in positioning the sensor unit to receive radiation 22 from the area of the structure 16 5 exposed by the radiation 18. In step S7, the generator 12 generates electromagnetic radiation 18 including the exposure and reference wavelengths for the water-soluble substance. In step S8, the sensor unit 14 senses the radiation 22 from the structure area exposed by the radiation 18 at the exposure and reference wavelengths. The radiation 22 is derived from the radiation 18 either as an unabsorbed portion thereof 10 that is reflected or transmitted through the structure 16, or as an emission wavelength excited by the radiation 18. The sensor unit 14 senses the radiation 18 at the detection and reference wavelengths of the water-soluble substance to determine intensity levels for such wavelengths. In step S8, a predetermined area of the structure 16 is exposed with the generated radiation 18. In step S9, the radiation 22 15 that results from exposure of the structure 16 to the radiation 18, is received from the exposed area of the structure by the sensor unit 14. In step S10, the received radiation 22 is sensed by the sensor unit 14 to determine a first intensity level at the detection wavelength and a second intensity level at the reference wavelength. In step S 1 1 of Fig. 813, the intensity levels of the detection and reference 20 wavelength(s) for the watersoluble substance are compared. In step S 12, a determination is made to establish whether the intensity levels of the detection and reference wavelengths of the water-soluble substance differ by the predetermined amount. If the determination of step S12 is affimnative, in step S13, the water-soluble substance is determined to be present in the exposed area of the 25 structure. Conversely, if the determination in step S12 is negative, in step S14, the water-soluble substance is determined riot to be present in the exposed area of the structure 16. After performance of steps S 13 or S 14, the method of 1. igs. 8A and 8B ends in step S15. Steps S11 - S15 call be performed by either the processor 28, the computer 36 or a human user of the method.

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VIII. A Method for Detecting the Presence (or Absence) of Fungi in a Structure In Fig. 9, a method for detecting the presence of a fungi in a structure begins in step Sl. In step S2, the generator 12 is positioned to expose a predetermined area of the structure 16. In step S3, the sensor unit 14 is positioned to receive and sense 5 electromagnetic radiation 22 from the exposed area of the structure. In step S4, the generator 12 generates the electromagnetic radiation 18 including at least one wavelength significantly absorbed by fungi. In step S5, the generator 12 exposes the predetermined area of the structure 16 with the electromagnetic radiation 18 including at least one wavelength that is significantly absorbed by Fungi. In step S6, 10 the sensor unit 14 receives the electromagnetic radiation 22 from the exposed area of the structure 16. The received radiation 22 is based on or derived from the radiation 18, and can be a portion of such radiation which is reflected from or transmitted through the exposed area of the structure, or can be radiation at an emission wavelength of fungi that is excited by the radiation 18. In step S7, the sensor unit 14 15 senses the received radiation 22. In step S8, a determination is performed to establish whether the exposed area of the structure 16 contains fungi. If the determination in step S8 is affirmative, in step S9, fungi is determined to be present in the structure 16. On the other hand, if the result of the determination in step S8 is negative, in step SID, fungi is determined not to be present in the structure 16. After 20 performance of steps S9 or S10, in step Sit, the method of Fig. 9 ends. Steps S8-S11 can be performed by either the processor 28, the computer 36 or a human user of the method.

IX. A Relatively Specific Embodiment of the Method for Detecting the Presence (or Absence) of Fungi in a Structure 25 A relatively specific embodiment of the method for detecting the presence of lungi in a structure 16 begins in step S1 of Fig. 10A. In step S2, exposure wavelength(s) significantly absorbed by fungi, and not significantly absorbed by either water or the material composing the structure l 6, are determined.

Alternatively, the exposure wavelength can be determined to be one that excites 30 emission at an emission wavelength from fungi if present in the area of the structure to be exposed. For example, the exposure wavelength could be generated at 289 -29

nanometers (urn) using a frecuency-shifted 266 nm diode-pumped Nd:YAG laser as the generator 12 which excites emission from tryptophan at an emission wavelength of from 300 nm to 400 nrn. Because tryptophan is present in all biological materials, its presence in the structure 16 is indicative of the presence of fungi therein. In step 5 S3, a reference wavelength(s) not significantly absorbed by fungi, water and the material composing the structure 16, is determined. Such reference wavelengths could include 1.06 and 1.66 microns. Alternatively, if the exposure wavelength excites emission from fungi, the reference wavelength can be one at which no significant emission occurs, and that is not significantly absorbed by water or the 10 material composing the structure 16. In step S4, a detection wavelength(s) is determined that is sensitive to the exposure wavelength(s) in the presence of fungi, but not to water and the material composing the structure 16. The detection wavelength(s) can be the same as the exposure wavelength(s), or alternatively, can be an emission wavelength(s) of fungi that is excited by the exposure wavelength(s).

15 In step S5, the generator 12 is positioned to expose a predetermined area of the structure 16. Step S5 can be performed by a human user of the method using the stand 20. Optionally, the generator 12 can generate radiation 18 including visible wavelengths that permit such user to determine the area of the structure 16 that will be exposed by the radiation 18. The generator 12 could also include a view finder to 20 permit the user to determine the area of the structure 16 that will be exposed by the generator 12. In step S6, the sensor unit 14 is positioned to receive and sense the electromagnetic radiation 22 from the exposed area of the structure 16. Step S6 can be performed by the user by moving the stand 35 to position the sensor unit 14 to receive radiation 22 from the area of the structure 16 that is to be exposed with the 25 radiation 18. Alternatively, the sensor unit 14 can include a view finder to assist in positioning the sensor unit 14 on the stand 35 so that it will receive the radiation 22 from the area of the structure 16 that is exposed by the radiation 18. This operation is facilitated if the generator 12 generates the radiation 18 to include visible wavelengths that can readily indicate the exposed area of the structure 16 to the user.

30 The area of the structure 16 that is to be exposed by radiation 18 can also be marked with a removable substance such as chalk or ink to assist in alignment of the sensor -30

unit 14 relative to such marking. In step S7, the generator 12 generates the electromagnetic radiation 18 including the determined exposure and reference wavelengths. In step S8, the generator 12 exposes the predetermined area of the structure 16 with the generated radiation 18. In step S9, the sensor unit 14 receives 5 the radiation 22 resulting from exposure of the structure with the radiation 18, from the exposed area of the structure 16. In step Sin, the sensor unit 14 senses the received radiation 22 to determine a first intensity level for the detection wavelength(s) and a second intensity level for the reference wavelength. In step S 1 1 of Fig. lOB, the first and second intensity levels are compared. In step S12, a 10 determination is remade to establish whether the first and second intensity levels differ by a predetermined amount. If the determination in step Sl2 is affirmative, in step Sl3, fungi is, determined to be present in the exposed area of the structure 16. On the other hand, if the determination of step S12 is negative, in step S14, fungi are determined not to be present in the exposed area of the structure 16. After 15 performance of steps S 13 or S 14, the method of Figs. I OA and 1 OB ends in step S 15.

Steps S11 -S15 can be performed either by the processor 28, the computer 3 6 or a human user of the method of Figs. 1 OA and I OB.

The many features and advantages of the present invention are apparent from the detailed specification and thus, it is intended by the appended claims to cover all

20 such features and advantages of the described methods which follow in the scope of the invention. Further, since numerous modifications and changes will readily occur to those of ordinary skill in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described. Accordingly, all suitable modifications and equivalents may be resorted to as falling within the scope of the 25 invention. Industrial Applicability

The disclosed methods have industrial applicability in the detection and remediation

of water problems in a building, house, or other structure. The disclosed methods also can be used to detect mold or fungi that inhabit moist areas of structures, and 30 that can pose health concerns to person living or working in their presence.

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Claims

1. A method comprising the steps of: a) exposing with a generator a predetermined area of a structure to 5 first electromagnetic radiation including at least one predetermined wavelength absorbed by fungi; b) sensing with a sensor unit second electromagnetic radiation from the structure, the second radiation based on the first radiation; and c) determining whether the fungi is present in the exposed area of lo the structure, based on the second radiation sensed in said step (b).

2. A method as claimed in claim 1, wherein the generator comprises a laser. is 3. A method as claimed in claim 1, wherein the generator comprises a frequency-shifted diode-pumped Nd:YAG laser.

4. A method as claimed in claim 1, wherein the first electromagnetic radiation has a wavelength of two-hundred eighty-nine (289) nanometers.

5. A method as claimed in claim 1, wherein the first electromagnetic radiation has a wavelength that is absorbed by tryptophan in fungi.

6. A method as claimed in claim 1, wherein the second electromagnetic Is radiation has a wavelength from three-hundred (3()0) to four-hundred (400) nanometers. 7. A method as claimed in claim 1, wherein a wavelength of the first electromagnetic radiation used to expose the predetermined area of the so structure in step (a) is identical to a wavelength of the second

electromagnetic radiation sensed in step (b) and used in step (c) to determine whether fungi is present in the exposed area of the structure by comparing intensities of the first and second electromagnetic radiation.

s 8. A method as claimed in claim 1, wherein the second electromagnetic radiation results from emission from fungi caused by absorption of the first electromagnetic radiation.

9. A method as claimed in claim l, wherein the determining of step (c) is lo performed by a computer.

10. A method as claimed in claim 1, wherein the determining of step (c) is performed by a human operator.

Is ll. A method as claimed in claim 1, wherein the predetermined area exposed in step (a) is at least one square meter.

] 2. A method as claimed in claim 1, wherein the structure is a house to 13. A method as claimed in claim 1, wherein the structure is a building.

14. A method comprising the steps of: a) exposing with a generator a predetermined area of a structure to electromagnetic radiation including at least one predetermined exposure Is wavelength significantly absorbed by lungi, and at least one predetermined reference wavelength that is not significantly absorbed by the fungi; b) sensing with a sensor unit electromagnetic radiation from the exposed predetermined area of the structure at a predetermined detection wavelength that is sensitive to the exposure wavelength if the fungi is so present in the exposed predetermined area of the structure, and that is not

sensitive to the exposure wavelength if the fungi is not present in the exposed predetermined area of the structure, and at the reference wavelength; and c) determining whether the exposed predetermined area of the s structure includes the fungi, based on the electromagnetic radiation sensed in said step (b) at the detection and reference wavelengths.

15. A method as claimed in claim 14, wherein the generator comprises a laser. 16. A method as claimed in claim 14, wherein the generator comprises a frequency-shifted diode-pumped Nd:YAG laser.

17. A method as claimed in claim 14, wherein the exposure wavelength is is two hundred eighty-nine (289) nanometers.

18. A method as claimed in claim 14, wherein the first electromagnetic radiator has a wavelength that is absorbed by tryptophan in fungi.

20 19. A method as claimed in claim 14, wherein the reference wavelength is 1.06 micrometers.

20. A method as claimed in claim 14, wherein the reference wavelength is 1.66 micrometers.

2]. A method as claimed in Claire]4, wl:erein the detection wavelength is

from three-hundred (300) to four-hundred (400) nanometers.

22. A method as claimed in claim 14, wherein the exposure wavelength is so identical to the detection wavelength.

23. A method as claimed in claim 14, wherein electromagnetic radiation at the detection wavelength results from emission from fungi excited by absorption of electromagnetic radiation at the exposure wavelength.

24. A method as claimed in claim 14, wherein the exposure, reference, and detection wavelengths are not significantly absorbed by the material composing the structure.

lo 25. A method as claimed in claim 24, wherein the exposure, reference, and detection wavelengths are not significantly absorbed by water.

26. A method as claimed in claim 14, wherein the exposure, reference, and detection wavelengths are not significantly absorbed by water.

27. A method as claimed in claim 14, wherein the determining of step (c) is perfonned a computer.

28. A method as claimed in claim 14, wherein the determining of step (c) so is perfonned by a human operator.

29. A method as claimed in claim 14, wherein the predetermined area exposed in step (a) is at least one square meter.

as 30. A method as claimed ire claim 14, wherein the structure is a house.

31. A method as claimed in claim 14, wherein the structure is a building.