US3783284A
Expired / Lapsed
US
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Method and apparatus for detection of petroleum products
Assignee: Texas Instruments Inc
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Filing: 1971-10-28
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Granted: 1974-01-01
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Expires: 1991-10-28
Abstract
Abstract Disclosed is a method and apparatus for indicating the presence or absence of petroleum products in a water area by utilizing an active infrared source which illuminates the water area which may contain a petroleum product. The reflected infrared radiation is filtered by two filters at two different wavelengths, lambda 1 and 2. Two infrared detectors produce signals which are proportional to the detected reflected radiation at the wavelengths 1 and 2. A processing channel is connected to each detector, the processing channels each including a log amplifier, the output of which is coupled to a differencing circuit which produces an output signature signal, 1n (V(1)/V(2)), which indicates either the presence or absence of the petroleum products in the water area.
Inventors
- 👤 K Mccormack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:41
CPC Classifications
G; G01; G01V; G01V8/00; G01V8/02; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/314
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
133 words
A method for indicating the presence or absence of petroleum and petroleum products in a water area comprising the steps of: a. illuminating an open water area with modulated infrared radiation; b. collecting and focusing the modulated infrared radiation reflected from said area; c. detecting substantially simultaneously the reflected focused infrared radiation from said area at wavelengths lambda 1 and lambda 2 adjacent to resonant wavelength of water and petroleum or petroleum products respectively; d. producing electrical signals representative of the reflected infrared radiation detected at the wavelengths lambda 1 and lambda 2; and e. determining electrically the ratio of the electrical signals representative of the reflected infrared radiation whereby ratios less than one indicate water and ratios greater than one indicate the presence of petroleum or petroleum products in the water area.
Claim 2
Independent Claim
133 words
A method for indicating the presence or absence of petroleum and petroleum products in a water area comprising the steps of: a. illuminating an open water area with modulated infrared radiation; b. collecting and focusing the modulated infrared radiation reflected from said area; c. detecting substantially simultaneously the reflected focused infrared radiation from said area at wavelengths lambda 1 and lambda 2 adjacent to resonant wavelength of water and petroleum or petroleum products respectively; d. producing electrical signals representative of the reflected infrared radiation detected at the wavelengths lambda 1 and lambda 2; and e. determining electrically the ratio of the electrical signals representative of the reflected infrared radiation whereby ratios less than one indicate water and ratios greater than one indicate the presence of petroleum or petroleum products in the water area.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein lambda 1 is betWeen about 2.9 and 3.4 microns and lambda 2 is between about 3.4 and 4.2 microns.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said reflected radiation is detected more than 30 feet from said water area.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein each of said steps (a) through (e) are repeated at a plurality of locations.
Claim 6
Dependent Claim
54 words
The method of claim 1 wherein said signals representative of the reflected radiant energy at wavelengths lambda 1 and lambda 2 are log signals, and wherein determining said ratio includes forming the ln V( lambda 1)/V( lambda 2) such that a log ratio greater than 0 indicates the absence of petroleum or petroleum products.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein lambda 1 is approximately 3.4 microns.
Claim 8
Dependent Claim
12 words
The method of claim 5 wherein lambda 2 is approximately 4.2 microns.
Claim 9
Dependent Claim
29 words
The method of claim 1 further including monitoring said electrically determined ratios to actuate an alarm condition when said electrically determined ratios indicates the presence of said petroleum products.
Claim 10
Dependent Claim
92 words
The method according to claim 1 wherein the step of determining electrically the ratio of the electrical signals at the lambda 1 and lambda 2 wavelengths representative of the reflected infrared radiation comprises (i) processing the signals in first and second log amplifier circuits to produce signals ln V( lambda 1)/VB1 ln 1n V( lambda 1)/VB2 respectively; and (ii) weighting the signals by setting the bias voltage VB1 and VB2 to cancel each other in a difference amplifier to produce an output signature signal Phi 12 ln r( lambda 1)/r( lambda 2).
Claim 11
Independent Claim
225 words
A system for indicating the presence of petroleum type material in an open water area comprising: a. an infrared radiation source means positioned independently of the water surface for impinging a beam of infrared radiation upon the open water area; b. chopper means in the beam path of the source of infrared radiation for modulating the beam; c. means operative to collect and focus infrared radiation reflected from the water area; d. filtering means including first and second filters in the focusing path of the reflected infrared radiation operative to pass infrared radiation of first and second wavelengths, lambda 1 and lambda 2, adjacent to resonant wavelength of water and petroleum type material, respectively; e. first and second detectors positioned to receive respectively the reflected focused infrared radiation of wavelengths lambda 1 and lambda 2 and operative to produce electrical signals representative thereof; f. first and second log amplifier channels coupled to the first and second detectors operative to produce a pair of signals equal respectively to the log values of the reflected radiation at lambda 1 and lambda 2 wavelengths; and g. a signal differencing means coupled to the first and second log amplifier channels responsive to the pair of signals indicative of the log values of the reflected radiation for providing a signature signal representative of the ratio of the pair of signals.
Claim 12
Independent Claim
225 words
A system for indicating the presence of petroleum type material in an open water area comprising: a. an infrared radiation source means positioned independently of the water surface for impinging a beam of infrared radiation upon the open water area; b. chopper means in the beam path of the source of infrared radiation for modulating the beam; c. means operative to collect and focus infrared radiation reflected from the water area; d. filtering means including first and second filters in the focusing path of the reflected infrared radiation operative to pass infrared radiation of first and second wavelengths, lambda 1 and lambda 2, adjacent to resonant wavelength of water and petroleum type material, respectively; e. first and second detectors positioned to receive respectively the reflected focused infrared radiation of wavelengths lambda 1 and lambda 2 and operative to produce electrical signals representative thereof; f. first and second log amplifier channels coupled to the first and second detectors operative to produce a pair of signals equal respectively to the log values of the reflected radiation at lambda 1 and lambda 2 wavelengths; and g. a signal differencing means coupled to the first and second log amplifier channels responsive to the pair of signals indicative of the log values of the reflected radiation for providing a signature signal representative of the ratio of the pair of signals.
Claim 13
Dependent Claim
31 words
The system of claim 10 wherein lambda 1 is approximately in the range of 2.9 to 3.4 microns and lambda 2 is approximately in the range of 3.4 to 4.2 microns.
Claim 14
Dependent Claim
14 words
The system of claim 10 wherein said means for illuminating is a laser means.
Claim 15
Dependent Claim
14 words
The system of claim 42 wherein said means for illuminating is a discharge tube.
Claim 16
Dependent Claim
12 words
The system of claim 10 wherein lambda 1 is approximately 3.4 microns.
Claim 17
Dependent Claim
39 words
The system of claim 10 wherein said signature signal is greater than zero when there are no petroleum products present in said area and said signature signal is less than zero when petroleum products are present in said area.
Claim 18
Dependent Claim
42 words
The system of claim 10 wherein a plurality of said systems are located at different locations along a water area to thereby produce a plurality of siGnature signals which indicate the presence or absence of petroleum products at each of said locations.
Claim 19
Independent Claim
202 words
A system for indicating the presence or absence of petroleum or petrolum products in a water area comprising: a. an infrared source means positioned independently of the water surface for directing a modulated beam of infrared energy to illuminate the water area; b. means operative to collect and focus the infrared radiation reflected from the water area; c. filtering means including first and second filters in the focusing path of the reflected infrared radiation operative to pass infrared radiation adjacent the resonant wavelengths of water and petroleum or petroleum products; d. detector means positioned to receive substantially simultaneously the reflected infrared radiation passing the first and second filters of the filter means and providing a pair of radiation signals that are a function of the infrared radiation in the two different frequency bands adjacent the resonant frequencies; and e. circuit means coupled to said first and second detectors and responsive to the pair of reflected radiation signals, said circuit means providing a signal that is a function of the ratio between said signals and which is independent of variations of surface conditions and weighted whereby a ratio less than one indicates whether petroleum or petroleum products are present in the water area.
Claim 20
Independent Claim
202 words
A system for indicating the presence or absence of petroleum or petrolum products in a water area comprising: a. an infrared source means positioned independently of the water surface for directing a modulated beam of infrared energy to illuminate the water area; b. means operative to collect and focus the infrared radiation reflected from the water area; c. filtering means including first and second filters in the focusing path of the reflected infrared radiation operative to pass infrared radiation adjacent the resonant wavelengths of water and petroleum or petroleum products; d. detector means positioned to receive substantially simultaneously the reflected infrared radiation passing the first and second filters of the filter means and providing a pair of radiation signals that are a function of the infrared radiation in the two different frequency bands adjacent the resonant frequencies; and e. circuit means coupled to said first and second detectors and responsive to the pair of reflected radiation signals, said circuit means providing a signal that is a function of the ratio between said signals and which is independent of variations of surface conditions and weighted whereby a ratio less than one indicates whether petroleum or petroleum products are present in the water area.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |