US3853407A
Expired / Lapsed
US
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Multiple path spectrophotometer method and apparatus
Assignee: SENSORES CORP
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Filing: 1973-04-23
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Granted: 1974-12-10
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Expires: 1993-04-23
Abstract
Abstract A multiple path spectrophotometer system is disclosed in which the beam from a radiation source is selectively directed over a plurality of different paths which may contain sample material or reference material and is detected by a single detector. The radiation source is operable to provide a beam at a plurality of alternately selectable wavelengths and the detector detects the absorption effects of material within the selected path. The method uses three sequential paths in which one path has negligible absorption, one has known selective absorption and one has unknown selective absorption to be determined.
Inventors
- 👤 C Dewey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:43
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/314; G01J; G01J3/00; G01J3/02; G01J3/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
A method of spectrophotometry comprising: a. Placing a material exhibiting substantially spectrally uniform light absorption in a first channel of a spectrophotometer; b. placing a material having a negligible absorption of a predetermined first spectral band and known absorption of a predetermined second spectral band in a second channel of said spectrophotometer; c. placing a material having negligible absorption of said first spectral band and unknown absorption of said second spectral band in a third channel of said spectrophotometer; d. illuminating said channels sequentially with alternations of said first and second spectral bands; and e. detecting the illumination intensity passed by each channel in sequence so as to obtain information indicative of the nature of the material in said third channel.
Claim 2
Independent Claim
121 words
A method of spectrophotometry comprising: a. Placing a material exhibiting substantially spectrally uniform light absorption in a first channel of a spectrophotometer; b. placing a material having a negligible absorption of a predetermined first spectral band and known absorption of a predetermined second spectral band in a second channel of said spectrophotometer; c. placing a material having negligible absorption of said first spectral band and unknown absorption of said second spectral band in a third channel of said spectrophotometer; d. illuminating said channels sequentially with alternations of said first and second spectral bands; and e. detecting the illumination intensity passed by each channel in sequence so as to obtain information indicative of the nature of the material in said third channel.
Claim 3
Dependent Claim
25 words
A method of spectrophotometry according to claim 1 wherein said illuminating and detecting are all performed with a single light source and a single detector.
Claim 4
Dependent Claim
30 words
A method of spectrophotometry according to claim 1 further comprising processing said information to determine the concentration of a particular molecular species in the material placed in said third channel.
Claim 5
Dependent Claim
127 words
A method of spectrophotometry according to claim 3 in which said processing comprises solving the equation: C C* (Bo/Ao -Bs/As/Bo/Ao - Br/Ar) Where C is the concentration of the particular molecular species in the material placed in said third channel; C* is the known concentration in said second channel; Ao is the first spectral band intensity detected from said first channel; Bo is the second spectral band intensity detected from said first channel; Ar is the first spectral band intensity detected from said second channel; Br is the second channel; Br is the second spectral band intensity detected from said second channel; As is the first spectral band intensity detected from said third channel; and Bs is the second spectral band intensity detected from said third channel.
Claim 6
Independent Claim
166 words
A method of spectrophotometry comprising: a. Operating an illuminating source to provide alternations of a first spectral band and a second spectral band; b. measuring the intensity of light from the illuminating source to obtain a comparison of the energy in said first and second spectral bands; c. passing the filtered light through a first material having known absorption of said first spectral band and negligible absorption of said second spectral band; d. measuring the light intensity passed through said first material to obtain a comparison of the energy transmitted in said first and second spectral bands; e. passing the filtered light through a second material havinG unknown absorption in said first spectral band and negligible absorption in said second spectral band; f. measuring the light intensity passed through said second material to obtain a comparison of the energy transmitted in said first and second spectral bands; and, g. processing the three comparisons obtained in the preceding steps to determine the nature of said second material.
Claim 7
Independent Claim
166 words
A method of spectrophotometry comprising: a. Operating an illuminating source to provide alternations of a first spectral band and a second spectral band; b. measuring the intensity of light from the illuminating source to obtain a comparison of the energy in said first and second spectral bands; c. passing the filtered light through a first material having known absorption of said first spectral band and negligible absorption of said second spectral band; d. measuring the light intensity passed through said first material to obtain a comparison of the energy transmitted in said first and second spectral bands; e. passing the filtered light through a second material havinG unknown absorption in said first spectral band and negligible absorption in said second spectral band; f. measuring the light intensity passed through said second material to obtain a comparison of the energy transmitted in said first and second spectral bands; and, g. processing the three comparisons obtained in the preceding steps to determine the nature of said second material.
Claim 8
Dependent Claim
156 words
A spectrophotometer comprising: a. a single light source; b. a plurality of analysis channels; c. a rotatablle shaft positioned radially equidistant from each of said channels; d. first optical means mounted on one end of said shaft to selectively direct light from said source through said analysis channels; e. a single photodetector mounted on the opposite end of said shaft; f. second optical means mounted on said opposite end of said shaft to selectively intercept light from an analysis channel and bring it to a focus on said photodetector; g. a wavelength selector for selecting in alternation two spectral bands from said light source and transmitting the selected bands to said first optical means; and, h. third optical means for bringing light from said light source to a focus at said wavelength selector; said first optical means being further characterized in that it brings light from said source to a focus in the selected analysis channel.
Claim 9
Dependent Claim
156 words
A spectrophotometer comprising: a. a single light source; b. a plurality of analysis channels; c. a rotatablle shaft positioned radially equidistant from each of said channels; d. first optical means mounted on one end of said shaft to selectively direct light from said source through said analysis channels; e. a single photodetector mounted on the opposite end of said shaft; f. second optical means mounted on said opposite end of said shaft to selectively intercept light from an analysis channel and bring it to a focus on said photodetector; g. a wavelength selector for selecting in alternation two spectral bands from said light source and transmitting the selected bands to said first optical means; and, h. third optical means for bringing light from said light source to a focus at said wavelength selector; said first optical means being further characterized in that it brings light from said source to a focus in the selected analysis channel.
Claim 10
Dependent Claim
27 words
A spectrophotometer according to claim 6 further comprising means to drive said shaft in rotation whereby said light is sequentially directed through each of said analysis channels.
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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |