US4549809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for photometric measurement of light absorption of liquid samples in cuvettes
Assignee: Toshiba Corp
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Filing: 1983-09-28
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Granted: 1985-10-29
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Expires: 2003-09-28
Abstract
Abstract A photometric measurement method for producing readout signals indicative of light absorption of samples contained in a series of cylindrical cuvettes arranged in a movable cuvette carrier for successively conveying said cuvettes into the path of a measuring light beam directed onto a radiation detector, wherein readings are taken at precisely measured intervals as a function of the width of the cuvette, the rate of movement of the cuvette and the required number of measurements, and a selected reading is taken at the same distance from the leading wall of each cuvette.
Inventors
- 👤 Tomiharu Minekane
- 👤 Noboru Yokotani
- 👤 Takehiko Onuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:44
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27; G01N2201/00; G01N2201/04; G01N2201/0415
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
202 words
A method of photometric measurement of the light absorption of the contents of a cuvette moving at a predetermined rate through the path of a beam of light directed onto a light detector comprising the steps of: a. fixing the time intervals between readings of the measurements of the light absorption as a function of the width of the cuvette, the predetermined rate of movement of the cuvette through the light path, and the required number of readings; b. making an initial reading of the light absorptions in the light path immediately before the cuvette enters the light path; c. comparing the differences between successive readings and the initial reading until the difference exceeds a predetermined limit less than the peak value of the readings of the leading wall of the cuvette, indicating passage of the leading wall and the arrival of a predetermined portion of the cuvette; d. continuing readings until the desired number of readings is taken indicating the passage of the trailing wall of the cuvette; and e. selecting a measurement of light absorption at exactly the same attained position as to each cuvette, as the predetermined portion of the cuvette passes through the path of the light beam.
Claim 2
Independent Claim
202 words
A method of photometric measurement of the light absorption of the contents of a cuvette moving at a predetermined rate through the path of a beam of light directed onto a light detector comprising the steps of: a. fixing the time intervals between readings of the measurements of the light absorption as a function of the width of the cuvette, the predetermined rate of movement of the cuvette through the light path, and the required number of readings; b. making an initial reading of the light absorptions in the light path immediately before the cuvette enters the light path; c. comparing the differences between successive readings and the initial reading until the difference exceeds a predetermined limit less than the peak value of the readings of the leading wall of the cuvette, indicating passage of the leading wall and the arrival of a predetermined portion of the cuvette; d. continuing readings until the desired number of readings is taken indicating the passage of the trailing wall of the cuvette; and e. selecting a measurement of light absorption at exactly the same attained position as to each cuvette, as the predetermined portion of the cuvette passes through the path of the light beam.
Claim 3
Dependent Claim
41 words
The method of claim 1 including storing said width of the cuvette, predetermined rate of movement of the cuvette, the required number of readings, the predetermined limit in the memory of a microprocessor and making the required calculations in the microprocessor.
Claim 4
Dependent Claim
37 words
The method of claim 1 including a plurality of cuvettes arranged in a movable cuvette carrier, the cuvettes moving through a thermostaticized bath, or a like bath, and wherein said initial reading is taken through said bath.
Claim 5
Dependent Claim
33 words
The method of claim 1 including the step of converting the values output from said detector into digital form at predetermined times throughout the period of measurement of light absorption by the cuvette.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein said predetermined portion of the cuvette is the central portion thereof.
References Cited (Backward Citations)
US3966323A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |