US4596931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of eliminating measuring errors in photometric analysis
Assignee: Instrumentarium Oyj
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Filing: 1984-04-03
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Granted: 1986-06-24
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Expires: 2004-04-03
Abstract
Abstract The invention relates to a method of eliminating the effect of temperature, air pressure and/or a disturbing material component or a like parameter in photometric analysis in which is generated a so-called dark signal, the passage of emitted radiation for detection being blocked at that time, a reference signal for one or more material components to be measured, said reference signal not being affected by said material component to be measured, as well as for each material component to be measured a measuring signal representing the amount of material component to be measured. According to the invention, whenever the difference between a reference signal and a measuring signal changes due to a change in any of the above parameters, there is generated a control signal which represents said parametric change and is proportional thereto, said control signal serving to change the difference between a reference signal and a dark signal in order to compensate for said parametric change. The material components to be measured may preferably comprise CO 2 , N 2 O and/or one or more anesthetic gases.
Inventors
- 👤 Gosta Ehnholm
- 👤 Matti Hakala
- 👤 Tapio Uimonen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:08
CPC Classifications
G; G01; G01D; G01D3/00; G01D3/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
A method for eliminating the effects of an error producing parameter in the photometric measurement of one or more gaseous components, said method including the steps of: generating a dark signal establishing a zero level to which other signals used in the measurement are referred; generating a reference signal for the component being measured, said reference signal not being affected by the component; comparing said dark signal and said reference signal for establishing a desired signal difference between said signals; generating a measuring signal responsive to the component being measured, said signal being subject to the effects of the error producing parameter; comparing the reference signal and the measuring signal to provide an indication of the concentration of the component being measured; generating an error signal in accordance with the error producing parameter; and altering the signal difference between said dark and reference signals responsive to said error signal for altering said reference signal to eliminate the effect of the error producing parameter in the comparison of the reference signal and the measuring signal.
Claim 2
Independent Claim
174 words
A method for eliminating the effects of an error producing parameter in the photometric measurement of one or more gaseous components, said method including the steps of: generating a dark signal establishing a zero level to which other signals used in the measurement are referred; generating a reference signal for the component being measured, said reference signal not being affected by the component; comparing said dark signal and said reference signal for establishing a desired signal difference between said signals; generating a measuring signal responsive to the component being measured, said signal being subject to the effects of the error producing parameter; comparing the reference signal and the measuring signal to provide an indication of the concentration of the component being measured; generating an error signal in accordance with the error producing parameter; and altering the signal difference between said dark and reference signals responsive to said error signal for altering said reference signal to eliminate the effect of the error producing parameter in the comparison of the reference signal and the measuring signal.
Claim 3
Dependent Claim
32 words
The method as set forth in claim 1 further defined as one for eliminating the effects of at least one of temperature, pressure, and cross absorption property parameters in the photometric measurement.
Claim 4
Dependent Claim
46 words
The method as set forth in claim 2 further defined as comparing said dark and reference signal difference with a fixed signal for establishing the level of said reference signal, and as altering the reference signal level to eliminate the effect of the error producing parameter.
Claim 5
Dependent Claim
118 words
The method as set forth in claim 2 further defined as one for measuring first and second gaseous components and wherein reference and measuring signals are generated for each of said first and second components and wherein the step of generating the error signal is further defined as generating an error signal in accordance with the concentration of said first component for altering the signal difference between said dark signal and said reference signal for said second component, thereby to eliminate the effects of cross absorption, and as generating an error signal in accordance with the concentration of said second component for altering the signal difference between said dark signal and said reference signal for said first component.
Claim 6
Dependent Claim
33 words
The method as set forth in claim 1 wherein said dark and reference signals are subject to amplification and wherein said altering step is further defined as altering the gain of the amplification.
Claim 7
Dependent Claim
16 words
The method as set forth in claim 1 further defined as one for measuring carbon dioxide.
Claim 8
Dependent Claim
16 words
The method as set forth in claim 1 further defined as one for measuring anaesthetic gases.
Claim 9
Dependent Claim
18 words
The method as set forth in the claim 7 further defined as one for measuring N 2 O.
References Cited (Backward Citations)
US4153837A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |