Analytical optical instruments
First Claim
1. In a field instrument for pulse-light one-shot or cyclic in situ on-site measurement of such optical properties of a sunlight exposed fluid or of a fluid solid interface exposed to sunlight as reflection, flourescence, phosphorexcence, absorption and turbidity, the improvement comprising the combination of:
- electronically gated light source means for producing light pulses emitted at a prescribed repetition rate up to approximately 100 Hz, said source means including (a) a triggerable light source having the characteristics of a Xenon flash lamp which, when triggered, provides a brief pulse of light of extremely high intensity, and (b) control means for providing triggering pulses for operation of said light source;
multi-channel single probe means comprising an elongated tubular member containing two or more light channels including first channel means comprising first light-conducting fiber means for conveying each said pulse of light to a specific point in the said fluid at the site and a first light-conducting fiber-optic cable for conducting said pulses to said first light-conducting fiber means, said fiber-optic cable being so aligned with respect to said light source to provide an efficient light pipe;
second returned light channel means, comprising second light-conducting fiber means for collecting light emitted from a prescribed direction at said point being positioned to provide a maximum cone angle at the interface of the surface for receiving the emitted light collected by the second light-conducting fiber means and being shielded to remain in shadow relative to reflected light and a second light-conducting fiber-optic cable for conveying the light responding in said direction to said pulses;
means for measuring the light conveyed to the site and for measuring at least a prescribed portion of the light from the site along said second channel means;
sampling means for receiving (a) signals corresponding to light intensity conveyed to the site and (b) signals corresponding to said measurements of light from the site;
gated electronic means including a disabling circuit coupled to said sampling means and responsive to said triggering pulses for enabling said measuring means only prior to and during said brief occurence of said pulse of light, said measuring means including means for sensing the intensity of the pulse of light conveyed to the site and means for sensing the intensity of light returned from the site through said second light-conducting fiber-optic cable where said disabling circuit disables said measuring means after said pulse; and
means for storing the aforesaid signals representing light intensity, said storing means being updated on the occurrence of each pulse.
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Accused Products
Abstract
An optical measuring system for measuring in situ by means of one or more fiber-optic probes reflection absorption fluorescence, phosphorescence and turbidity of a fluid or (for all but the last measurement) of a fluid-solid interface. High intensity pulsed light is conveyed to the measurement site by a fiber-optic cable and is given a specific direction at the site by means of the geometry of the probe, reaction light resulting from the stimulating light pulse is discriminated by the geometry of the probe, or another probe, and is returned via a further fiber-optic cable to a measurement system which is enabled to sense the returning light only for the duration of the light pulse. The measurement system comprises means for sensing the relative intensity of the stimulating light pulse and for deriving a signal at least representative of the ratio of the magnitude of the quality sensed, by means of the probe, and the relative intensity of the stimulating light pulse. In one embodiment a unitary probe has three light channels, one conveying light to the site, one conveying light to the measurement system at least representative of the stimulating light intensity at the side and the last providing to the measurement system a signal representative of the magnitude of the quality of interest.
112 Citations
25 Claims
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1. In a field instrument for pulse-light one-shot or cyclic in situ on-site measurement of such optical properties of a sunlight exposed fluid or of a fluid solid interface exposed to sunlight as reflection, flourescence, phosphorexcence, absorption and turbidity, the improvement comprising the combination of:
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electronically gated light source means for producing light pulses emitted at a prescribed repetition rate up to approximately 100 Hz, said source means including (a) a triggerable light source having the characteristics of a Xenon flash lamp which, when triggered, provides a brief pulse of light of extremely high intensity, and (b) control means for providing triggering pulses for operation of said light source; multi-channel single probe means comprising an elongated tubular member containing two or more light channels including first channel means comprising first light-conducting fiber means for conveying each said pulse of light to a specific point in the said fluid at the site and a first light-conducting fiber-optic cable for conducting said pulses to said first light-conducting fiber means, said fiber-optic cable being so aligned with respect to said light source to provide an efficient light pipe; second returned light channel means, comprising second light-conducting fiber means for collecting light emitted from a prescribed direction at said point being positioned to provide a maximum cone angle at the interface of the surface for receiving the emitted light collected by the second light-conducting fiber means and being shielded to remain in shadow relative to reflected light and a second light-conducting fiber-optic cable for conveying the light responding in said direction to said pulses; means for measuring the light conveyed to the site and for measuring at least a prescribed portion of the light from the site along said second channel means; sampling means for receiving (a) signals corresponding to light intensity conveyed to the site and (b) signals corresponding to said measurements of light from the site; gated electronic means including a disabling circuit coupled to said sampling means and responsive to said triggering pulses for enabling said measuring means only prior to and during said brief occurence of said pulse of light, said measuring means including means for sensing the intensity of the pulse of light conveyed to the site and means for sensing the intensity of light returned from the site through said second light-conducting fiber-optic cable where said disabling circuit disables said measuring means after said pulse; and means for storing the aforesaid signals representing light intensity, said storing means being updated on the occurrence of each pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for measuring properties of a fluid substance on site and in situ, the system comprising:
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a light source having the characteristics of a Xenon flash tube which is triggerable to generate a flash pulse of light of high intensity over a broad spectrum of wavelengths; triggering means coupled to said light source to provide a trigger input thereto, said triggering means having a gate input and a signal input; cell-less single probe optical detecting means comprising first fiber-optic channel means for guiding pulsed light emanating from said light source down said probe toward a specific point of interest in the fluid; second fiber-optic channel means for collecting pulses of light emitted by the fluid at the said point of interest in response to the said light pulses transmitted thereto, said second fiber-optic channel means being positioned within said probe in a manner to provide a maximum light cone angle thereby maximizing light collecting efficiency and being positioned to minimize interference from reflected light; measuring means for (a) sensing the intensity of light conveyed to said point of interest at the site by said light source and (b) sensing the intersity of light travelling from said point of interest along said second channel means, said measuring means having an enable input; means, coupled to receive input from said measuring means,for storing one signal representing the sensed intensity of light conveyed to the site and another signal representing the sensed intensity of light travelling from the site along said second channel means; control means for coincidentally and synchronously selectively providing a gate pulse to said gate input of said triggering means and said measuring means said control means further including a disabling means to disable said measuring means; means for combining said one signal and said other signal to provide a measurement of an optical property of the sample substance; and wherein said control means is connected to the gate input of said triggering means and to the enable input of said measuring means and wherein gate pulses from said control means cause said triggering means to trigger said light source and said measuring means is enabled for substantially only the duration of each gate pulse. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. An optical instrument for measuring optical properties of a fluid at a prescribed site, comprising:
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(a) a light source for emitting a high intensity light pulse of predetermined duration, (b) first channel means for conveying said light pulses to the site, said first channel means comprising a first light-conducting probe and a first optical fiber where said optical fiber and light source are so aligned to enable light transmission therebetween, (c) second channel means for conveying light returning from the site, said second means comprising a second light-conducting probe and a second optical fiber, said second light conducting probe being positioned to provide a maximum cone angle to maximize collection from the site of light emitted by said first light conducting probe while minimizing the collection of ambient light and said first and second light conducting probe are in close proximity to each other, (d) first measuring means for sensing and measuring the intensity of light or selected portion thereof returned from the site through said second channel means, said measuring means generating a first signal corresponding to said light intensity, (e) second measuring means for measuring the gating control means for enabling said first measuring means during the entire occurrence of the light pulse, said control means being electrically connected to said light source and said first measuring means for synchronous and coincidental gating, (f) third measuring means for measuring the intensity of the light pulse from said light source and generating a second signal corresponding to said light pulse intensity, (g) storage means for storing said signal, and (h) means for providing a ratio between said first and second signals. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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Specification