LED fluorometer with remote detection capability
First Claim
1. A fluorometer for detecting the level of fluorescent material in a body of water, the fluorometer comprising:
- an excitation system including an excitation source for producing excitation light capable of causing fluorescence in fluorescent material; and
a detection system for detecting said fluorescence, whereinsaid excitation system comprises an excitation source comprising one or more light emitting diodes (LEDs), the excitation system further comprising means to cause said excitation light to form, in use, a generally conical divergent beam projecting from the fluorometer, said beam causing means comprising at least one collimating lens, said excitation system further including means for modulating said beam with a modulating signal having a modulating frequency, and whereinsaid detection system comprises means for receiving light and for converting said received light into a corresponding electrical signal, and at least one lens arranged to direct said received light onto said light receiving and converting means, wherein said at least one lens of the detection system is arranged to provide a generally conical convergent detection volume for the detection system, said generally conical detection volume converging in a direction towards said fluorometer and at least partially overlapping with said generally conical divergent beam and whereinsaid detection system further includes means for detecting, in the electrical signal produced by said light receiving and converting means, a signal component of substantially the same frequency as said modulation frequency, said detecting means including means for performing spectral analysis of said electrical signal and means for determining the value of a spectral component of said electrical signal corresponding to said modulation frequency,wherein said detection system is arranged to determine the level of fluorescent material present in said body of water depending on said value of said spectral component, such that the fluorometer is capable of detecting fluorescent material located remotely from the fluorometer in said body of water.
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Accused Products
Abstract
A fluorometer comprising an excitation system including an excitation source for producing excitation light capable of causing fluorescence in fluorescent material; and a detection system for detecting said fluorescence. The excitation source comprises one or more light emitting diodes (LEDs) associated with means for causing said excitation light to form a beam that projects, during use, from the fluorometer. In one embodiment, the excitation system and the detection system are located in respective separate housings, the angular disposition between the housings being adjustable. In other embodiments, the excitation system and the detection system are located in the same housing. The fluorometer is particularly suited for use in detecting leaks in aqueous environments, especially when mounted on an underwater vehicle.
25 Citations
37 Claims
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1. A fluorometer for detecting the level of fluorescent material in a body of water, the fluorometer comprising:
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an excitation system including an excitation source for producing excitation light capable of causing fluorescence in fluorescent material; and a detection system for detecting said fluorescence, wherein said excitation system comprises an excitation source comprising one or more light emitting diodes (LEDs), the excitation system further comprising means to cause said excitation light to form, in use, a generally conical divergent beam projecting from the fluorometer, said beam causing means comprising at least one collimating lens, said excitation system further including means for modulating said beam with a modulating signal having a modulating frequency, and wherein said detection system comprises means for receiving light and for converting said received light into a corresponding electrical signal, and at least one lens arranged to direct said received light onto said light receiving and converting means, wherein said at least one lens of the detection system is arranged to provide a generally conical convergent detection volume for the detection system, said generally conical detection volume converging in a direction towards said fluorometer and at least partially overlapping with said generally conical divergent beam and wherein said detection system further includes means for detecting, in the electrical signal produced by said light receiving and converting means, a signal component of substantially the same frequency as said modulation frequency, said detecting means including means for performing spectral analysis of said electrical signal and means for determining the value of a spectral component of said electrical signal corresponding to said modulation frequency, wherein said detection system is arranged to determine the level of fluorescent material present in said body of water depending on said value of said spectral component, such that the fluorometer is capable of detecting fluorescent material located remotely from the fluorometer in said body of water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A fluorometer for detecting the level of fluorescent material in a body of water, the fluorometer comprising:
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an excitation system including an excitation source for producing excitation light capable of causing fluorescence in fluorescent material; and a detection system for detecting said fluorescence, wherein said excitation system comprises an excitation source comprising one or more light emitting diodes (LEDs), the excitation system further comprising means for causing said excitation light to form, in use, a generally conical divergent beam projecting from the fluorometer, said beam causing means comprising at least one collimating lens arranged to cause said excitation light to form a substantially collimated elongate beam that projects, during use, from the fluorometer, and said excitation system further including means for modulating said collimated elongate beam with a modulating signal having a modulating frequency, said excitation system being arranged such that said beam is capable of causing fluorescence in fluorescent material at distances of up to several meters from the fluorometer, and wherein said detection system comprises means for receiving light and for converting said received light into a corresponding electrical signal, and at least one lens arranged to direct said received light onto said light receiving and converting means, wherein said at least one lens of the detection system is arranged to provide a generally conical convergent detection volume for the detection system, said generally conical detection volume converging in a direction towards said fluorometer and at least partially overlapping with said generally conical divergent beam, and wherein said detection system further includes means for detecting, in the electrical signal produced by said light receiving and converting means, a signal component of substantially the same frequency as said modulation frequency, said detecting means including means for performing spectral analysis of said electrical signal and means for determining the value of a spectral component of said electrical signal corresponding to said modulation frequency, wherein said detection system is arranged to determine the level of fluorescent material present in said body of water depending on said value of said spectral component such that the fluorometer is capable of detecting fluorescent material located remotely from the fluorometer at distances of up to several meters from the fluorometer in said body of water, and wherein the excitation system and the detection system are each provided in a respective housing, the respective housings being located adjacent one another and arranged such that there is an overlap, during use, between said generally conical divergent beam emanating from the excitation system housing and said generally conical convergent detection volume of the detection system housing, and wherein the respective housings have a respective longitudinal axis, said longitudinal axes being substantially parallel with one another, and said generally conical divergent beam and said generally conical convergent detection volume are substantially aligned with said respective longitudinal axis. - View Dependent Claims (34, 35)
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36. A method of determining the level of a fluorescent material in a body of water remotely from a fluorometer, the fluorometer comprising an excitation system including an excitation source for producing excitation light capable of causing fluorescence in fluorescent material;
- and a detection system for detecting said fluorescence, the method comprising;
generating said excitation light using at least one light emitting diode (LED); causing said excitation light to project from said excitation system in a generally conical divergent beam; using at least one collimating lens to form said divergent beam; modulating said beam with a modulating signal having a modulating frequency; receiving light at said detection system and converting said received light into a corresponding electrical signal; using at least one lens to provide a generally conical convergent detection volume for the detection system, said generally conical detection volume to converging in a direction towards said fluorometer; causing said generally conical detection volume to at least partially overlap with said generally conical divergent beam; detecting, in said electrical signal, a signal component of substantially the same frequency as said modulation frequency; determining the value of a spectral component of said electrical signal corresponding to said modulation frequency; and determining the level of fluorescent material present in said body of water depending on said value of said spectral component. - View Dependent Claims (37)
- and a detection system for detecting said fluorescence, the method comprising;
Specification