US3922095A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wavelength calibrator for clinical instruments
Assignee: Individual
•
Filing: 1973-06-01
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Granted: 1975-11-25
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Expires: 1993-06-01
Abstract
Abstract A device for calibrating a spectrophotometer or like device is disclosed. Spectrophotometers generally have an adjustable monochromator adapted to transmit a substantially monochromatic light beam through a sample cell. A detector measures the amount of light transmitted through the sample cell at different wavelengths to determine the composition of the sample. The present device comprises a probe adapted to be interposed in the light beam intermediate the monochromator and the detector in place of the sample cell. The probe has a narrow band-pass light filter having a known center wavelength which is exposed to the light beam, and photoconductive element located within the probe behind the filter so that light passing through the filter impinges on the photoconductive element. The photoconductive element has an electrical conductance proportionate to the radiant intensity of the light impinging on the element. Means are provided for measuring the conductance of the photoconductive element, and the monochromator is adjusted to achieve maximum transmittance through the filter. When maximum transmittance is achieved, the spectrophotometer has been calibrated at the center wavelength of the filter.
Inventors
- 👤 Jin G Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:02
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/02; G01J3/06; G01J2003/2866
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
126 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam, said apparatus comprising: a narrow-band light filter having a known center wavelength, said filter adapted to be interposed in the light beam; a photoelectric element adapted to be interposed in the light beam downstream of the light filter so that light passing through said filter impinges on said photoelectric element, said element having an electrical conductance proportional to the radiant intensity of said light impinging on said element; means for measuring the electrical conductance of the photoelectric element, whereby the monochromator or like device can be adjusted to obtain maximum transmittance through the light filter to calibrate the monochromator at the center wavelength of the filter.
Claim 2
Dependent Claim
126 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam, said apparatus comprising: a narrow-band light filter having a known center wavelength, said filter adapted to be interposed in the light beam; a photoelectric element adapted to be interposed in the light beam downstream of the light filter so that light passing through said filter impinges on said photoelectric element, said element having an electrical conductance proportional to the radiant intensity of said light impinging on said element; means for measuring the electrical conductance of the photoelectric element, whereby the monochromator or like device can be adjusted to obtain maximum transmittance through the light filter to calibrate the monochromator at the center wavelength of the filter.
Claim 3
Dependent Claim
42 words
Apparatus as in claim 1 wherein the resistance of the photoelectric element is responsive to the wavelength of the light impinging thereon, and wherein the peak response of said photoelectric element is generally matched to the center wavelength of the light filter.
Claim 4
Dependent Claim
70 words
Apparatus as in claim 1 and additionally comprising a portable probe containing said light filter and said photoelectric element, said probe having an aperture exposing the light filter so that the filter can be interposed in the output beam of the monochromator with the photoelectric element downstream of the light filter, and wherein the means for measuring the electrical conductance of the photoelectric element is connected to said portable probe.
Claim 5
Dependent Claim
39 words
Apparatus as in claim 1 wherein the means for measuring the electrical conductance of the photoelectric element comprises means for passing a current through the photoelectric element and means for measuring the passage of current through the photoelectric element.
Claim 6
Dependent Claim
143 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam to a detector, said apparatus comprising: a probe adapted to be inserted in the light beam intermediate the monochromator and the detector, said probe having a narrow band light filter with a known center wavelength adapted to be exposed to the light beam, and a photoelectric element located within the probe behind the filter so that light passing through said filter impinges on said photoelectric element, said element having an electrical conductance proportional to the radiant intensity of the light impinging on said element; and means connected to the probe for measuring the conductance of the photoelectric element, whereby said variable monochromator can be adjusted to achieve maximum transmittance through the filter to calibrate the spectrophotometer at the center wavelength of the filter.
Claim 7
Dependent Claim
143 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam to a detector, said apparatus comprising: a probe adapted to be inserted in the light beam intermediate the monochromator and the detector, said probe having a narrow band light filter with a known center wavelength adapted to be exposed to the light beam, and a photoelectric element located within the probe behind the filter so that light passing through said filter impinges on said photoelectric element, said element having an electrical conductance proportional to the radiant intensity of the light impinging on said element; and means connected to the probe for measuring the conductance of the photoelectric element, whereby said variable monochromator can be adjusted to achieve maximum transmittance through the filter to calibrate the spectrophotometer at the center wavelength of the filter.
Claim 8
Dependent Claim
42 words
Apparatus as in claim 5 wherein the conductance of the photoelectric element is responsive to the wavelength of the light impinging thereon, and wherein the peak wavelength of the photoelectric element is generally matched to the center wavelength of the light filter.
Claim 9
Dependent Claim
64 words
Apparatus as in claim 5 wherein the probe has a casing adapted to enclose the light filter and the photoelectric element, said casing having an aperture adapted to expose the light filter, and wherein the means for measuring the conductance of the photoelectric element are connected to the probe by means of lead lines emanating from said measuring means and attached to said probe.
Claim 10
Dependent Claim
53 words
Apparatus as in claim 5 and additionally comprising a plurality of probes, each of said probes having a light filter with a different center wavelength, and wherein said measuring means is releasably connectable to each said probe, whereby the spectrophotometer can be calibrated at a plurality of wavelengths using a single measuring means.
Claim 11
Dependent Claim
44 words
Apparatus as in claim 5 wherein the means for measuring the conductance of the photoelectric element comprises means for applying a voltage across the photoelectric element to pass an electric current through said element, and means for measuring the current through the photoelectric element.
Claim 12
Dependent Claim
39 words
Apparatus as in claim 9 wherein the means for measuring the current through the photoelectric element comprises a meter, and means for amplifying the current passing through the photoelectric element prior to passage of said current through said meter.
Claim 13
Dependent Claim
34 words
Apparatus as in claim 10 and additionally comprising variable resistance means intermediate the photoelectric element and the amplifier, said variable resistance means manually operable to provide selective control over the current to the meter.
Claim 14
Dependent Claim
23 words
Apparatus as in claim 10 and additionally comprising voltage regulating means intermediate the amplifier and the meter to prevent damage to said meter.
Claim 15
Dependent Claim
52 words
Apparatus as in claim 12 wherein the voltage regulating means comprises a grounded Zener diode, and additionally comprising a light emitting diode intermediate the Zener diode and ground, said light emitting diode being illuminated by passage of current through said Zener diode to ground, said illumination indicating potential overloading of said meter.
Claim 16
Dependent Claim
174 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam, said apparatus comprising: a probe adapted to be inserted in the light beam, said probe having an exposed filter adapted to allow passage of light of a known wavelength band into the interior of the probe, and photoelectric means interior to the probe and having an electrical conductance responsive to the radiant intensity of the light transmitted into said probe through the filter; means for applying voltage across the photoelectric means to pass a current through said photoelectric means responsive to the conductance of said element; means for amplifying the current passed through the photoelectric means; manually operable variable resistance means for tapping a selectable proportion of current intermediate the photoelectric means and the amplifying means to control the current to said amplifying means; a meter adapted to measure the amplified current; and means for tapping the amplified current prior to passage of said current through the meter to prevent overloading of said meter.
Claim 17
Dependent Claim
174 words
Apparatus for calibrating a spectrophotometer or like instrument having an adjustable monochromator adapted to transmit a substantially monochromatic light beam, said apparatus comprising: a probe adapted to be inserted in the light beam, said probe having an exposed filter adapted to allow passage of light of a known wavelength band into the interior of the probe, and photoelectric means interior to the probe and having an electrical conductance responsive to the radiant intensity of the light transmitted into said probe through the filter; means for applying voltage across the photoelectric means to pass a current through said photoelectric means responsive to the conductance of said element; means for amplifying the current passed through the photoelectric means; manually operable variable resistance means for tapping a selectable proportion of current intermediate the photoelectric means and the amplifying means to control the current to said amplifying means; a meter adapted to measure the amplified current; and means for tapping the amplified current prior to passage of said current through the meter to prevent overloading of said meter.
Claim 18
Dependent Claim
55 words
Apparatus as recited in claim 14 wherein the means for tapping the amplified current comprises a grounded Zener diode, and a light emitting diode intermediate the Zener diode and ground, said light emitting diode being illuminated by passage of current through said Zener diode to ground, said illumination thereby indicating potential overloading of said meter.
Claim 19
Independent Claim
165 words
A method for calibrating a spectrophotometer or like instrument having an adjustable monochromatoR adapted to transmit a substantially monochromatic light beam to a detector, said method comprising the steps of: inserting a probe in the light beam intermediate the monochromator and the detector so that a narrow-band light filter with a known center wavelength forming part of the probe is exposed to the light beam, a photoelectric element being located within the probe behind the filter so that light passing through the filter impinges on the photoelectric element which has an electrical conductance proportional to the radiant intensity of the light impinging on said element; measuring the conductance of the photoelectric element with means connected to the probe; visually indicating the conductance of the photoelectric element to indicate the intensity of light passing through the light filter; and adjusting the monochromator until the intensity of light passing through the light filter is a maximum to calibrate the spectrophotometer at the center wavelength of the filter.
Claim 20
Independent Claim
165 words
A method for calibrating a spectrophotometer or like instrument having an adjustable monochromatoR adapted to transmit a substantially monochromatic light beam to a detector, said method comprising the steps of: inserting a probe in the light beam intermediate the monochromator and the detector so that a narrow-band light filter with a known center wavelength forming part of the probe is exposed to the light beam, a photoelectric element being located within the probe behind the filter so that light passing through the filter impinges on the photoelectric element which has an electrical conductance proportional to the radiant intensity of the light impinging on said element; measuring the conductance of the photoelectric element with means connected to the probe; visually indicating the conductance of the photoelectric element to indicate the intensity of light passing through the light filter; and adjusting the monochromator until the intensity of light passing through the light filter is a maximum to calibrate the spectrophotometer at the center wavelength of the filter.
References Cited (Backward Citations)
US3780631A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |