US4722905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductors
Assignee: BTG International Ltd
•
Filing: 1982-11-30
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Granted: 1988-02-02
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Expires: 2002-11-30
Abstract
Abstract A gas sensor element comprising a film of a semiconducting compound of formula I supported by a non-conductive substrate, the film being disposed between conductors for supplying a current to the film and withdrawing a current therefrom. ##STR1## in which: M represents 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt or Pd; R 1 represents H, CH 3 , Cl, Br, I, CN, CO 2 H, COOC n H 2n+1 , CONH 2 or NO 2 ; R 2 represents H or CH 3 ; and R 3 a and R 3 b , which may be identical or different represent H, NO 2 , Cl, CO 2 H or CH 3 ; provided that when M represents cobalt at least one of R 1 , R 2 , R 3 a and R 3 b is other than hydrogen.
Inventors
- 👤 Colin L. Honeybourne
- 👤 Richard J. Ewen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:52
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/125; G01N27/126; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
118 words
A gas sensor which is highly sensitive to low levels of gas or vapor, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR4## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-donating substituents; or wherein R 1 is an electron-withdrawing substituent, R 2 is an electron-donating substituent and at least one of R 3 a and R 3 b is a methyl group and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd.
Claim 2
Dependent Claim
118 words
A gas sensor which is highly sensitive to low levels of gas or vapor, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR4## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-donating substituents; or wherein R 1 is an electron-withdrawing substituent, R 2 is an electron-donating substituent and at least one of R 3 a and R 3 b is a methyl group and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd.
Claim 3
Dependent Claim
13 words
The gas sensor of claim 1, wherein M is 2H, Cu or Ni.
Claim 4
Dependent Claim
78 words
The gas sensor of claim 1, wherein the electron-donating substituents R 1 , R 2 , R 3 a and R 3 b are each a methyl group; or at least one of R 3 a and R 3 b is a methyl group, and the electron-withdrawing substituent R 1 is selected from the group consisting of Cl, Br, I, CN, CO 2 H, CO 2 C 2 H 5 , CONH 2 , NO 2 or H.
Claim 5
Dependent Claim
16 words
The gas sensor of claim 3, wherein the electron-withdrawing substituent R 1 is Cl or Br.
Claim 6
Independent Claim
182 words
A method of detecting low levels of gas or vapor with high sensitivity, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR5## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-donating substituents, or wherein R 1 is an electron-withdrawing substituent, R 2 is an electron-donating substituent and at least one of R 3 a and R 3 b is a methyl group and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd; supported on a non-conducting substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 7
Independent Claim
182 words
A method of detecting low levels of gas or vapor with high sensitivity, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR5## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-donating substituents, or wherein R 1 is an electron-withdrawing substituent, R 2 is an electron-donating substituent and at least one of R 3 a and R 3 b is a methyl group and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd; supported on a non-conducting substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 8
Dependent Claim
93 words
A gas sensor which is capable of gas uptake at high gas concentrations in which uptake is substantially reversible, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR6## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-withdrawing substituents; and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd.
Claim 9
Dependent Claim
93 words
A gas sensor which is capable of gas uptake at high gas concentrations in which uptake is substantially reversible, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR6## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-withdrawing substituents; and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd.
Claim 10
Dependent Claim
53 words
The gas sensor of claim 6, wherein the electron-withdrawing substituents R 1 , R 2 , R 3 a and R 3 b are each selected from the group consisting of Cl, Br, I, CN, CO 2 H, CO 2 C 2 H 5 , CONH 2 , NO 2 or H groups.
Claim 11
Dependent Claim
29 words
The gas sensor of claim 7, wherein said R 1 , R 2 , R 3 a and R 3 b groups are each Br or NO 2 .
Claim 12
Independent Claim
161 words
A method of detecting high concentrations of gas or vapor with a gas sensor whose gas or vapor uptake is substantially reversible, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR7## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-withdrawing substituents; and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential difference is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 13
Independent Claim
161 words
A method of detecting high concentrations of gas or vapor with a gas sensor whose gas or vapor uptake is substantially reversible, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR7## wherein the substituents R 1 , R 2 , R 3 a and R 3 b are electron-withdrawing substituents; and M is selected from the group consisting of 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt and Pd; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential difference is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 14
Dependent Claim
92 words
A gas sensor which is highly sensitive to low levels of gas or vapor, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR8## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is H, CH 3 or CO 2 Et and M is selected from the group consisting of 2H, Cu and H.
Claim 15
Dependent Claim
92 words
A gas sensor which is highly sensitive to low levels of gas or vapor, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR8## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is H, CH 3 or CO 2 Et and M is selected from the group consisting of 2H, Cu and H.
Claim 16
Independent Claim
156 words
A method of detecting low levels of gas or vapor with high sensitivity, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR9## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is H, CH 3 or CO 2 Et and M is selected from the group consisting of 2H, Cu and H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 17
Independent Claim
156 words
A method of detecting low levels of gas or vapor with high sensitivity, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR9## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is H, CH 3 or CO 2 Et and M is selected from the group consisting of 2H, Cu and H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to said film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 18
Dependent Claim
86 words
A gas sensor which is capable of gas uptake at high gas concentrations in which uptake is substantially reversible, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR10## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is Cl or NO 2 ; and M is 2H.
Claim 19
Dependent Claim
86 words
A gas sensor which is capable of gas uptake at high gas concentrations in which uptake is substantially reversible, which comprises a gas sensitive film of a semiconducting compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR10## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is Cl or NO 2 ; and M is 2H.
Claim 20
Independent Claim
154 words
A method of detecting high concentrations of gas or vapor with a gas sensor whose gas or vapor uptake is substantially reversible, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR11## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is Cl or NO 2 ; and M is 2H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to the film, whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 21
Independent Claim
154 words
A method of detecting high concentrations of gas or vapor with a gas sensor whose gas or vapor uptake is substantially reversible, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR11## wherein the substituents R 3 a and R 3 b are each H or CH 3 , R 2 is H, R 1 is Cl or NO 2 ; and M is 2H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current to the film and withdrawing a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to the film, whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 22
Dependent Claim
89 words
A gas sensor which is both highly sensitive to low levels of gas or vapor and also capable of gas uptake at high gas concentrations wherein said uptake uptake is substantially reversible, which comprises a gas sensitive film of a semiconductive compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR12## wherein M is 2H and each and all of R 1 , R 2 , R 3 a R 3 b are H.
Claim 23
Dependent Claim
89 words
A gas sensor which is both highly sensitive to low levels of gas or vapor and also capable of gas uptake at high gas concentrations wherein said uptake uptake is substantially reversible, which comprises a gas sensitive film of a semiconductive compound, said film being supported on a non-conductive substrate and being disposed between spaced apart conductors, and wherein said semiconducting compound has the formula: ##STR12## wherein M is 2H and each and all of R 1 , R 2 , R 3 a R 3 b are H.
Claim 24
Independent Claim
138 words
A method of detecting low levels of gas or vapor with high sensitivity or detecting high concentrations of gas or vapor in a substantially reversible manner, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR13## wherein each and all of M, R 1 , R 2 , R 3 a R 3 b are H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to the film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
Claim 25
Independent Claim
138 words
A method of detecting low levels of gas or vapor with high sensitivity or detecting high concentrations of gas or vapor in a substantially reversible manner, which comprises: (a) exposing a gas or a vapor to a film of a gas sensor element comprising a gas sensitive film of a semiconducting compound of the formula: ##STR13## wherein each and all of M, R 1 , R 2 , R 3 a R 3 b are H; supported on a non-conductive substrate, said film being disposed between spaced apart conductors for supplying a current therefrom; while a potential differential is supplied to said film; and (b) applying a current to the film; whereby the current supplied to said film and withdrawn therefrom is increased due to the presence of said gas or vapor, the increase in current being signalled.
References Cited (Backward Citations)
US3930884A
Cited
GB1435760A
Cited
DE2334918A1
Cited
DE2335403A1
Cited
US3974040A
Cited
US4381922A
Cited
US4236307A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
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