US3617136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colorimeter and elements therefor
Assignee: Pollution Monitors Inc
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Filing: 1970-06-15
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Granted: 1971-11-02
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Expires: 1990-06-15
Abstract
Abstract This invention is addressed to a new and improved colorimeter for determining the concentration of gaseous pollutants in air and to improved scrubber and photocell assemblies for use with such colorimeters, wherein the scrubber includes a helical coil into which an air sample is drawn and admixed with a liquid absorbent whereby the liquid flows gravitationally through the coil in the form of wave fronts to provide complete contact between the air sample and the liquid absorbent with minimum agitation, and the photocell assembly includes a pair of spaced photoresistors and light source spaced therebetween, with the light source having a lamp housing enclosing the light source and defining a pair of spaced openings whereby the light source projects optical spots to the photoresistors to illuminate the photoresistors with light, the relative intensity of which is dependent upon the color developed in solutions passed in front of the photoresistors as an indication of the pollutant gas concentration in the air sample.
Inventors
- 👤 Norman A Lyshkow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:36
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/85
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
222 words
A photocell assembly for a colorimeter comprising a pair of spaced opposing cell housings, each of said housing defining a central opening therethrough adapted to receive tube means for passage of a liquid therethrough and each defining a second opening transverse to said central opening terminating in a recess adapted to receive a photoresistor on opposing faces of said housings, a photoresistor in each recess, a light source between said cell housings, and adjacent thereto, said light source being coincident with the axis defined by said second openings transparent tube means extending through each of said central openings between said light source and said photoresistor, and a lamp housing on said light source mounted for rotation about said light source, said lamp housing defining a pair of openings therethrough spaced about said lamp housing by an angle less than 180* but at aN angle whereby said light source projects an optical spot simultaneously through the openings in said lamp housing and through each second opening and said tube means in said cell housing to illuminate said photoresistors and whereby the resistance of each of the photoresistors can be balanced by rotating the lamp housing to vary simultaneously the relative intensity of light projected through the openings in said lamp housing and means to detect the difference between the resistance of the photoresistors.
Claim 2
Dependent Claim
222 words
A photocell assembly for a colorimeter comprising a pair of spaced opposing cell housings, each of said housing defining a central opening therethrough adapted to receive tube means for passage of a liquid therethrough and each defining a second opening transverse to said central opening terminating in a recess adapted to receive a photoresistor on opposing faces of said housings, a photoresistor in each recess, a light source between said cell housings, and adjacent thereto, said light source being coincident with the axis defined by said second openings transparent tube means extending through each of said central openings between said light source and said photoresistor, and a lamp housing on said light source mounted for rotation about said light source, said lamp housing defining a pair of openings therethrough spaced about said lamp housing by an angle less than 180* but at aN angle whereby said light source projects an optical spot simultaneously through the openings in said lamp housing and through each second opening and said tube means in said cell housing to illuminate said photoresistors and whereby the resistance of each of the photoresistors can be balanced by rotating the lamp housing to vary simultaneously the relative intensity of light projected through the openings in said lamp housing and means to detect the difference between the resistance of the photoresistors.
Claim 3
Dependent Claim
25 words
A photocell assembly as defined in claim 1 wherein said lamp housing is a substantially cylindrical housing having said openings on the peripheral surface thereof.
Claim 4
Dependent Claim
31 words
A photocell assembly as defined in claim 2 wherein said openings in said lamp housing are spaced about the periphery of the cylindrical housing by a distance of about 170* .
Claim 5
Dependent Claim
29 words
A photocell assembly as defined in claim 1 which includes a color filter in said recess of each cell housing interposed between said tube means and said photo resistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |