EP0105659A2
Expired / Lapsed
EP
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Carbon monoxide detectors
Assignee: Babcock and Wilcox Co
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Filing: 1983-09-20
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Granted: —
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Expires: 2003-09-20
Abstract
Abstract A carbon monoxide detector comprises a single monochromatic infra-red source (12) which is arranged to alternately direct light through two separate gas-containing test chambers (16,18). A first (16) of the chambers is supplied with gas to be tested, which has an 'unknown carbon monoxide content. A catalytic burning chamber (32) is connected between the chambers (16, 18) to receive gas from the first chamber (16), burn the carbon monoxide in the gas to carbon dioxide, and supply the carbon monoxide free gas to the second chamber (18). A single infra-red light detector (24) is provided for receiving light as it comes alternately from the two chambers (16, 18). The light from the two chambers (16, 18) is compared to determine the amount of carbon monoxide present in the gas of the first test chamber (16). Since the same background gas is provided in both of the chambers (16. 18) and only a single infra-red source and detector are utilised, inaccuracies due to differences in background detection, infra-red source intensity and infra-red sensitivity are overcome.
Inventors
- 👤 Andre Thomas Abromaitis
- 👤 Marion A. Keyes Iv
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 16:59
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; G01N21/75; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N33/004; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
199 words
A carbon monoxide detector comprising a source (12) of infra-red radiation, a measuring chamber (16) for receiving a gas to be tested for carbon monoxide, and a reference chamber (18) for receiving a gas, characterised in that: a reaction chamber (32) is connected between the measuring and reference chambers (16, 18) for converting carbon monoxide to carbon dioxide and for receiving gas from the measuring chamber (16) and supplying gas which is free of carbon monoxide to the reference chamber (18); the measuring and reference chambers (16, 18) have infra-red transparent means defining first and second infra-red radiation paths therethrough; beam splitting means is associated with the source (12) for directing infra-red radiation along the first and second paths; an infra-red detector (24) is provided for detecting infra-red radiation of the first and second paths after the radiation has passed through the measuring and reference chambers (16, 18), respectively; and circuit means is connected to the detector (24) for determining a difference between the infra-red radiation of the first and second paths absorbed in the measuring and reference chambers (16, 18), which difference is a function of the carbon monoxide concentration of gas supplied to the measuring chamber (16).
Claim 2
Dependent Claim
199 words
A carbon monoxide detector comprising a source (12) of infra-red radiation, a measuring chamber (16) for receiving a gas to be tested for carbon monoxide, and a reference chamber (18) for receiving a gas, characterised in that: a reaction chamber (32) is connected between the measuring and reference chambers (16, 18) for converting carbon monoxide to carbon dioxide and for receiving gas from the measuring chamber (16) and supplying gas which is free of carbon monoxide to the reference chamber (18); the measuring and reference chambers (16, 18) have infra-red transparent means defining first and second infra-red radiation paths therethrough; beam splitting means is associated with the source (12) for directing infra-red radiation along the first and second paths; an infra-red detector (24) is provided for detecting infra-red radiation of the first and second paths after the radiation has passed through the measuring and reference chambers (16, 18), respectively; and circuit means is connected to the detector (24) for determining a difference between the infra-red radiation of the first and second paths absorbed in the measuring and reference chambers (16, 18), which difference is a function of the carbon monoxide concentration of gas supplied to the measuring chamber (16).
Claim 3
Dependent Claim
46 words
A carbon monoxide detector according to claim 1, wherein the beam splitting means comprises a beam splitter (14) for receiving infra-red radiation from the source (12) and supplying half of the radiation to the measuring chamber (16) and half of'the radiation to the reference chamber (18).
Claim 4
Dependent Claim
34 words
A carbon monoxide detector according to claim 1 or claim 2, including an infra-red reflector (26, 28) in each of the first and second paths for reflecting infra-red radiation to the infra-red detector (24).
Claim 5
Dependent Claim
30 words
A carbon monoxide detector according to claim 1, claim 2 or claim 3, wherein the reaction chamber (32) comprises a catalytic chamber for catalytically converting carbon monoxide to carbon dioxide.
Claim 6
Dependent Claim
76 words
A carbon monoxide detector accroding to any one of the preceding claims, wherein the circuit means comprises circuit elements for establishing the carbon monoxide concentration (C l ) according to the function where A and A2 are calibration constants, I OUT-2 is the intensity of the infra-red radiation supplied to the detector (24) from the second path and I OUT-1 is the intensity of the infra-red radiation supplied to the detector (24) along the first path.
Claim 7
Dependent Claim
44 words
. 6. A carbon monoxide detector according to any one of the preceding claims, wherein each of the infra-red transparent means includes a Pockel effect chopper (20) for transmitting infra-red radiation to the measuring and reference chambers (16, 18), respectively, at sequentially different times.
References Cited (Backward Citations)
No citation records indexed.
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