EP0156232A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multiwavelength spectrophotometer
Assignee: Hitachi Ltd
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Filing: 1985-03-12
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Granted: —
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Expires: 2005-03-12
Abstract
Abstract Light from a light source is dispersed by a grating. Two multichannel light detectors are arranged for detecting the dispersed light. One light detector detects the first order of interference and the other light detector detects the second order of interference in overlapping wavelength ranges. The outputs of the two light detectors are averaged for improving the S/N ratio, particularly in wavelength ranges in which the light intensity of the light source is low.
Inventors
- 👤 Taro Nogami
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 11:33
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/2803
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A multiwavelength spectrophotometer, particularly for liquid chromatography comprising a light source (1), a sample cell (3), a grating (5) for dispersing a light beam from said light source (1) and a first multichannel light detector (6) for detecting light dispersed by said grating (5) in a first wavelength range characterized by a second multichannel light detector (7) for detecting light dispersed by said grating (5) in a second wavelength range overlapping at least partly said first wavelength range said light detected by said second multichannel light detector (7) having a different order of interference in comparison to the order of interference of said light detected by said first multichannel light detector (6) and a processor (8) for averaging output signals of each of said first and second light detectors (6, 7).
Claim 2
Dependent Claim
131 words
A multiwavelength spectrophotometer, particularly for liquid chromatography comprising a light source (1), a sample cell (3), a grating (5) for dispersing a light beam from said light source (1) and a first multichannel light detector (6) for detecting light dispersed by said grating (5) in a first wavelength range characterized by a second multichannel light detector (7) for detecting light dispersed by said grating (5) in a second wavelength range overlapping at least partly said first wavelength range said light detected by said second multichannel light detector (7) having a different order of interference in comparison to the order of interference of said light detected by said first multichannel light detector (6) and a processor (8) for averaging output signals of each of said first and second light detectors (6, 7).
Claim 3
Dependent Claim
37 words
A spectrophotometer as claimed in claim 1, characterized in that said second light detector (7) is arranged for detecting the light in a wavelength range in which the light intensity of said light source (1) is low.
Claim 4
Dependent Claim
36 words
A spectrophotometer as claimed in claim 1 or 2, characterized in that said first light detector (6) detects the first order of interference and that said second light detector (7) detects the second order of interference.
Claim 5
Dependent Claim
57 words
A spectrophotometer as claimed in one of claims 1 to 3, characterized in that said light source (1) is a deuterium lamp, said first light detector (6) detects the first order of interference of the ultraviolet and visible wavelength ranges and said second light detector (7) detects the second order of interference of the visible wavelength range.
Claim 6
Dependent Claim
45 words
A spectrophotometer as claimed in claim 4, characterized in that said first light detector (6) detects the light in a wavelength range from 200 to 600 nm and said second light detector (7) detects the light in a wavelength range from 400 to 600 nm.
Claim 7
Dependent Claim
100 words
A spectrophotometer as claimed in one of claims 3 to 5, characterized in that the two light detectors (6, 7) are identical photodiode arrays and that the averaging of the output signals of the two photodiode arrays (6, 7) follows the following formula whereby, A is the output signal of a photodiode of the first array (6) covering a predetermined wavelength range, B(1) and B(2) are the output signals of two neighbouring photodiodes of the second array (7) covering together the same predetermined wavelength range and k 1 , k 2 are weight factors for the output signals A and
Claim 8
Dependent Claim
50 words
A photospectrometer as claimed in one of claims 1 to 5 characterized in that said first light detector and said second light detector are constructed integrally whereby a part of said one single light detector (60) detects one order of interference and the other part detects another order of interference.
References Cited (Backward Citations)
No citation records indexed.
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