US3897155A
Expired / Lapsed
US
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Atomic fluorescence spectrometer
Assignee: Unisearch Ltd
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Filing: 1973-08-01
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Granted: 1975-07-29
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Expires: 1993-08-01
Abstract
Abstract An improved atomic fluorescence spectrometer in which good correlation between output signal and concentration of sample is achieved by providing a dual channel biomodal detection system for the detection of modulated signals. This detection system provides means to allow for scattered light intensity as well as non-fluorescent emitted light. An improved method of detection of square or approximately square modulated signals allows information to be derived from the signals during up to 80 percent of elapsed time. Attachment of memory means with arithmetic capability allows automatic processing of output data.
Inventors
- 👤 Lloyd Earle Smythe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:17
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6402; G01N21/6404
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
171 words
An apparatus for atomic fluorescence spectrometry in which a true correlation between the output signal and the concentration of an element in a sample under analysis is obtained, substantially free of the effects of scattering, emission and background radiation, comprising: a. means for producing and modulating a sample light beam and directing the same to atomic vapor containing the element to be analyzed; b. means for producing an atomic vapor of an element to be analyzed and for receiving said sample light beam; c. two means, each for receiving and measuring light signals from said atomic vapor, one said means detecting and measuring light intensity at a wavelength at which the element under analysis flouresces, and the other said means detecting and measuring scattered light intensity at a wavelength at which said sample light beam has a strong flux but at which said element does not fluoresce; d. and means for subtracting from said detected and measured light representing fluorescent and scattered light, the detected and measured light representing scattered light.
Claim 2
Independent Claim
171 words
An apparatus for atomic fluorescence spectrometry in which a true correlation between the output signal and the concentration of an element in a sample under analysis is obtained, substantially free of the effects of scattering, emission and background radiation, comprising: a. means for producing and modulating a sample light beam and directing the same to atomic vapor containing the element to be analyzed; b. means for producing an atomic vapor of an element to be analyzed and for receiving said sample light beam; c. two means, each for receiving and measuring light signals from said atomic vapor, one said means detecting and measuring light intensity at a wavelength at which the element under analysis flouresces, and the other said means detecting and measuring scattered light intensity at a wavelength at which said sample light beam has a strong flux but at which said element does not fluoresce; d. and means for subtracting from said detected and measured light representing fluorescent and scattered light, the detected and measured light representing scattered light.
Claim 3
Dependent Claim
52 words
An apparatus according to claim 1, wherein the means for modulating the sample light beam imparts a substantially square waveform to the sample beam, and each said measuring means is such that it measures the square modulated emitted and scattered light signal continuously when the level of the modulation is not changing.
Claim 4
Dependent Claim
15 words
An apparatus according to claim 1, wherein each said measuring means produces a digital output.
Claim 5
Dependent Claim
40 words
An apparatus according to claim 3, which further comprises means to achieve digital output in each said measuring means by directing the output of a photosensitive detector to a voltage to frequency converter which is coupled to digital counting means.
Claim 6
Dependent Claim
22 words
An apparatus according to claim 1, wherein means for recording the measurements in each said measuring means by printed output are included.
Claim 7
Dependent Claim
27 words
An apparatus according to claim 1, wherein memory means with arithmetic capacity and readout capability are included for processing and storing measurements from both said measuring means.
References Cited (Backward Citations)
US3565567A
Cited
US3669544A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |