Patent US3646331A successfully refreshed from Google Patents.
US3646331A
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US
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Automatic 100{11 line adjustment of spectrophotometers
Assignee: Kollmorgen Corp
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Filing: 1970-09-03
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Granted: 1972-02-29
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Expires: 1990-09-03
Abstract
Abstract A method and apparatus for correcting radiation measuring errors in a spectrophotometer by digitizing the output of a 100-percent line input at selected discrete wavelengths. Each of the digitized values represent the spectrophotometer response at a particular wavelength. A factor, called an M factor is computed from the output at each discrete wavelength such that the digitized output multiplied by the M factor will give a corrected 100-percent output at each wavelength. These factors are each stored, and then when a sample is measured by the spectrophotometer, each of the stored M factors are synchronously applied to multiply the input signal derived from the sample thereby generating a corrected output.
Inventors
- 👤 Joseph Samuel Lord
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:02
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27; G01N21/274; G01J; G01J3/00; G01J3/28
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
A method of correcting error in a spectrophotometer comprising the steps of generating a first spectrophotometer output in response to illumination at discrete wavelengths from a standard reference source, calculating a correction factor at each of a selected plurality of wavelengths, said correction factors being the ratio of a constant to said first output, storing said correction factors, generating a second spectrophotometer output in response to illumination at discrete wavelengths from a test source, said test source including a sample to be tested, and multiplying said second output at each of said selected plurality of wavelengths by the corresponding calculated correction factor.
Claim 2
Independent Claim
102 words
A method of correcting error in a spectrophotometer comprising the steps of generating a first spectrophotometer output in response to illumination at discrete wavelengths from a standard reference source, calculating a correction factor at each of a selected plurality of wavelengths, said correction factors being the ratio of a constant to said first output, storing said correction factors, generating a second spectrophotometer output in response to illumination at discrete wavelengths from a test source, said test source including a sample to be tested, and multiplying said second output at each of said selected plurality of wavelengths by the corresponding calculated correction factor.
Claim 3
Dependent Claim
87 words
The method of claim 1 further comprising the steps of deriving first and second signals in response to illumination at discrete wavelengths from a pair of matched standard references, digitally determining the ratio of said first and second signals, said ratio being said first output, deriving third and fourth signals in response to illumination at discrete wavelengths from a sample and one of said pair of standard references, respectively, and digitally determining the ratio of said third to said fourth signals, said ratio being said second output.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said calculating step comprises the step of subtracting said first output from 2.
Claim 5
Dependent Claim
28 words
The method of claim 3 wherein said subtracting step comprises the steps of digitally deriving the complement of said first output, and adding said derived complement to 2.
Claim 6
Dependent Claim
31 words
The method of claim 2 wherein said multiplying step comprises the step of electronically adjusting the amplification of said third signal by the corresponding correction factor at each of said wavelengths.
Claim 7
Dependent Claim
19 words
The method of claim 5 wherein said calculating step comprises the step of subtracting said first output from 2.
Claim 8
Dependent Claim
97 words
A spectrophotometer comprising means for generating a first output at each of a plurality of discrete wavelengths from a standard reference source, means for generating a second output at each of said plurality of discrete wavelengths from a test source, said test source including a sample, digital means for calculating the ratio of a constant to said first output at each of said plurality of wavelengths, said ratio being a correction factor, means for storing said correction factors, and means for multiplying said second output at each of said plurality of wavelengths by said corresponding correction factor.
Claim 9
Dependent Claim
97 words
A spectrophotometer comprising means for generating a first output at each of a plurality of discrete wavelengths from a standard reference source, means for generating a second output at each of said plurality of discrete wavelengths from a test source, said test source including a sample, digital means for calculating the ratio of a constant to said first output at each of said plurality of wavelengths, said ratio being a correction factor, means for storing said correction factors, and means for multiplying said second output at each of said plurality of wavelengths by said corresponding correction factor.
Claim 10
Dependent Claim
141 words
The spectrophotometer of claim 7 wherein said means for generating a first output comprises means responsive to a pair of matched standard references for generating a first and second signal, and means for deriving a first ratio of said first signal to said second signal, said means for generating a second output comprises means responsive to a sample for generating a third signal, means responsive to one of said standard references for generating a fourth signal, and means for deriving a second ratio of said third signal to said fourth signal, said digital means for calculating a ratio comprises means for calculating the ratio of unity to said first ratio, said calculated ratio being a correction factor, and said means for multiplying comprises means for multiplying said second ratio at each of said plurality of wavelengths by said corresponding correction factor.
Claim 11
Dependent Claim
27 words
The spectrophotometer of claim 8 wherein said means for calculating the ratio of unity to said first ratio comprises means for subtracting said first ratio from 2.
Claim 12
Dependent Claim
38 words
The spectrophotometer of claim 9 wherein said means for subtracting said first ratio from 2 comprises means for obtaining the digital complement of said first ratio, and means for adding said complement of said first ratio to 2.
Claim 13
Dependent Claim
37 words
The spectrophotometer of claim 9 whErein said means for multiplying comprises means for multiplying at each of said plurality of wavelengths said third signal derived from said sample by the corresponding correction factor at each corresponding wavelength.
Claim 14
Dependent Claim
47 words
The spectrophotometer of claim 11 wherein said means for multiplying said third signal comprises an amplifier for amplifying said third signal, and electronic means for adjusting the gain of said amplifier at each of said plurality of wavelengths to equal the correction factor at each corresponding wavelength.
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |