US4049503A — Electrochemical gas detection

Claim 1

Independent Claim 126 words

In an electrochemical gas detector for measuring traces of a component of a gas mixture comprising a cell comprising two electrodes and an organic electrolyte between and in contact with said electrodes, an outer closing circuit connected to said electrodes for flow of an electric current through the electrolyte and the outer closing circuit, said outer closing circuit including measuring means responsive to flow of current in the outer closing circuit, means for introducing a gas mixture into said cell, said cell being adapted for contacting the gas mixture with the electrolyte for changing the electrochemical equilibrium at one of the electrodes for generation of an electrical current in the outer closing circuit, the improvement which comprises said electrolyte consisting essentially of an anhydrous organic gel.

Claim 2

Dependent Claim 126 words

In an electrochemical gas detector for measuring traces of a component of a gas mixture comprising a cell comprising two electrodes and an organic electrolyte between and in contact with said electrodes, an outer closing circuit connected to said electrodes for flow of an electric current through the electrolyte and the outer closing circuit, said outer closing circuit including measuring means responsive to flow of current in the outer closing circuit, means for introducing a gas mixture into said cell, said cell being adapted for contacting the gas mixture with the electrolyte for changing the electrochemical equilibrium at one of the electrodes for generation of an electrical current in the outer closing circuit, the improvement which comprises said electrolyte consisting essentially of an anhydrous organic gel.

Claim 3

Dependent Claim 20 words

Detector of claim 1, wherein said anhydrous organic gel is based on an anhydrous organic solvent and a synthetic polymer.

Claim 4

Dependent Claim 23 words

Detector of claim 2, wherein the polymer is a linear-macromolecular substance whose chain length corresponds to a molecular weight of at least 50,000.

Claim 5

Dependent Claim 12 words

Detector of claim 2, wherein the polymer and solvent are homopolar molecules.

Claim 6

Dependent Claim 21 words

Detector of claim 2, wherein the gel is doped with a salt which dissociates in the organic solvent for the polymer.

Claim 7

Dependent Claim 11 words

Detector of claim 5, wherein the salt is KPF 6 .

Claim 8

Dependent Claim 18 words

Detector of claim 2, wherein the organic solvent contains a carbonyl, alkoxyl, hydroxyl or phosphoric acid ester group.

Claim 9

Dependent Claim 22 words

Detector of claim 2, wherein the polymer is a homopolymer of an olefinically unsaturated compound, or a copolymer of olefinically unsaturated compounds.

Claim 10

Dependent Claim 21 words

Detector of claim 8, wherein the polymer is of at least one monomer of the group monovinyl monomers and monovinylidene monomers.

Claim 11

Dependent Claim 48 words

Detector of claim 2, wherein the polymer is polyvinyl chloride and the solvent is of the group acetoxy cyclohexane, ethylene glycol diacetate, benzoic acid ethyl ester, γ-butyrolactone, diethylene glycol monobutyl ether, 4,4-dimethyl-1,3-dioxane, methyl cyclohexyl acetate, lactic acid ethyl ester, oxalic acid diethyl ester, propylene carbonate and butylene carbonate.

Claim 12

Dependent Claim 27 words

Detector of claim 2, wherein the polymer is polyacrylonitrile and the solvent is of the group γ-butyrolactone, caprolactone, 1-methyl-2-pyrrolidone, phosphoric acid-tris-dimethyl amide, propylene carbonate and butylene carbonate.

Claim 13

Dependent Claim 52 words

Detector of claim 2, wherein the polymer is polymethyl methacrylate and the solvent is of the group acetoxy cyclohexane, benzoic acid ethyl ester, γ-butyrolactone, caprolactone, diethylene glycol monobutyl ether, 2,2-dimethyl-3-butanone, 4,4-dimethyl-1,3-dioxane, 2,2-dimethyl-4-hydroxy methyl-1,3,-dioxolane, 1-methyl-4-cyclohexanol, methyl cyclohexanone, methyl cyclohexyl acetate, 1-methyl-2-pyrrolidone, lactic acid ethyl ester, phosphoric acid-tris-dimethyl amide, propylene carbonate and butylene carbonate.

Claim 14

Dependent Claim 47 words

Detector of claim 2, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, and said polymer is polymethyl methacrylate or polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additive sodium benzoate and benzoic acid, and is doped with iron (III) sulphate.

Claim 15

Dependent Claim 43 words

Detector of claim 2, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, and said polymer is polyacrylonitrile, and said solvent is γ-butyrolactone, and the electrolyte contains as additives sodium benzoate and benzoic acid and is doped with iron (III) sulphate.

Claim 16

Dependent Claim 45 words

Detector of claim 2, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, said polymer is polymethyl methacrylate, and said solvent is propylene carbonate or phosphoric acid-tris-dimethyl amine, and the electrolyte contains as additive potassium hexafluorophosphate and is doped with iron (III) sulphate.

Claim 17

Dependent Claim 44 words

Detector of claim 2, suitable for detecting hydrogen sulfide, wherein the said one electrode comprises silver, said polymer is polymethyl methacrylate, and said solvent is propylene carbonate and the electrolyte contains as additive triethanolamine and acetic acid, and is doped with iron (III) sulphate.

Claim 18

Dependent Claim 42 words

Detector of claim 2 suitable for measuring sulfur dioxide, wherein the said one electrode comprises silver, said polymer is polyacrylonitrile, and said solvent is propylene carbonate and the electrolyte contains as additive triethanolamine and acetic acid, and is doped with silver sulphate.

Claim 19

Dependent Claim 45 words

Detector of claim 2, suitable for measuring sulfur dioxide, wherein the said one electrode comprises silver, said polymer is polyacrylonitrile, and said solvent is γ-butyrolactone, and the electrolyte contains as additives triethanolamine and acetic acid, and is doped with silver sulphate and iron (III) sulphate.

Claim 20

Dependent Claim 49 words

Detector of claim 2, suitable for measuring nitrogen dioxide, wherein one electrode comprises carbon and the other electrode comprises gold or carbon, and said polymer is polymethyl methacrylate,and said solvent is phosphoric acid-tris-dimethyl amine, and the electrolyte contains as additive potassium hexafluorophosphate, and is doped with iron (III) sulphate.

Claim 21

Dependent Claim 39 words

Detector of claim 2, suitable for measuring oxygen, wherein one electrode comprises silver and the other electrode comprises lead, said polymer is polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additive triethanolamine and acetic acid.

Claim 22

Dependent Claim 41 words

Detector of claim 2, suitable for measuring hydrogen fluoride, wherein one electrode comprises zirconium and the other electrode comprises zirconium or platinum, said polymer is polymethyl methacrylate, and said solvent is propylene carbonate, and the electrolyte contains as additive acetic acid.

Claim 23

Dependent Claim 87 words

Detector of claim 2, suitable for measuring chlorine wherein said one electrode comprises platinum, said polymer is polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additives tolylic acid and sodium benzoate, and is doped with iron (III) sulphate, and means for polarizing the electrodes during measurement by the application of a voltage in such a way that only a very weak current flows, so that the flow of depolarization current triggered off by the chlorine is a measure of the concentration of chlorine.

Claim 24

Dependent Claim 37 words

Detector of claim 1, wherein the gel has an electrical conductivity of at least 10 -5 ohm -1 cm - , a dielectric constant of at least 20 and a dipole moment of at least 2.0 Debye.

Claim 25

Dependent Claim 51 words

Detector of claim 1, comprising a cylinder having a hollow space therein in which there is a ring surrounding the gel electrolyte which is closed off by a measuring electrode on one side which is exposed to the gas to be measured, and by a counter electrode on the other side.

Claim 26

Dependent Claim 65 words

Detector of claim 24, wherein the detector is in the form of a throughflow measuring cell having a throughflow element mounted on said cylinder, said throughflow element having an inlet bore for conveying gas to the measuring electrode for passage of gas passed the measuring electrode, and an outlet bore for receiving gas passed by the measuring electrode and discharging the gas from the detector.

Claim 27

Dependent Claim 62 words

Detector of claim 1, comprising a member having an opening therein, the gel electrolyte being mounted in said opening, the get electrolyte being provided with a measuring electrode so that a triple phase interface of the gas, measuring electrode and electrolyte is formed on one side of the electrolyte and the other side of the gel electrolyte being provided with a counterelectrode.

Claim 28

Dependent Claim 9 words

Detector of claim 26, wherein said opening is cylindrical.

Claim 29

Dependent Claim 87 words

Process of measuring the concentration of a reactable component in a gas which comprises contacting the gas with the electrolyte of a detector cell according to claim 1 for reaction of said component to an extent proportional to the concentration of said component in the gas for generation of electric current in said closing circuit to an extent proportional to the concentration of said component in the gas, and measuring an effect on said current as a measure of the concentration of said component in the gas.

Claim 30

Dependent Claim 20 words

Process of claim 28, wherein said anhydrous organic gel is based on an anhydrous organic solvent and a synthetic polymer.

Claim 31

Dependent Claim 23 words

Process of claim 29, wherein the polymer is a linear-macromolecular substance whose chain length corresponds to a molecular weight of at least 50,000.

Claim 32

Dependent Claim 12 words

Process of claim 29, wherein the polymer and solvent are homopolar molecules.

Claim 33

Dependent Claim 21 words

Process of claim 29, wherein the gel is doped with a salt which dissociates in the organic solvent for the polymer.

Claim 34

Dependent Claim 11 words

Process of claim 32, wherein the salt is KPF 6 .

Claim 35

Dependent Claim 18 words

Process of claim 29, wherein the organic solvent contains a carbonyl, alkoxyl, hydroxyl or phosphoric acid ester group.

Claim 36

Dependent Claim 22 words

Process of claim 29, wherein the polymer is a homopolymer of an olefinically unsaturated compound, or a copolymer of olefinically unsaturated compounds.

Claim 37

Dependent Claim 21 words

Process of claim 35, wherein the polymer is of at least one monomer of the group monovinyl monomers and monovinylidene monomers.

Claim 38

Dependent Claim 48 words

Process of claim 29, wherein the polymer is polyvinyl chloride and the solvent is of the group acetoxy cyclohexane, ethylene glycol diacetate, benzoic acid ethyl ester, γ-butyrolactone, diethylene glycol monobutyl ether, 4,4-dimethyl-1,3-dioxane, methyl cyclohexyl acetate, lactic acid ethyl ester, oxalic acid diethyl ester, propylene carbonate and butylene carbonate.

Claim 39

Dependent Claim 27 words

Process of claim 29, wherein the polymer is polyacrylonitrile and the solvent is of the group γ-butyrolactone, caprolactone, 1-methyl-2-pyrrolidone, phosphoric acid-tris-dimethyl amide, propylene carbonate and butylene carbonate.

Claim 40

Dependent Claim 52 words

Process of claim 29, wherein the polymer is polymethyl methacrylate and the solvent is of the group acetoxy cyclohexane, benzoic acid ethyl ester, γ-butyrolactone, caprolactone, diethylene glycol monobutyl ether, 2,2-dimethyl-3-butanone, 4,4-dimethyl-1,3-dioxane, 2,2-dimethyl-4-hydroxy methyl-1,3,-dioxolane, 1-methyl-4-cyclohexanol, methyl cyclohexanone, methyl cyclohexyl acetate, 1-methyl-2-pyrrolidone, lactic acid ethyl ester, phosphoric acid-tris-dimethyl amide, propylene carbonate and butylene carbonate.

Claim 41

Dependent Claim 47 words

Process of claim 29, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, and said polymer is polymethyl methacrylate or polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additive sodium benzoate and benzoic acid, and is doped with iron (III) sulphate.

Claim 42

Dependent Claim 43 words

Process of claim 29, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, and said polymer is polyacrylonitrile, and said solvent is γ-butyrolactone, and the electrolyte contains as additives sodium benzoate and benzoic acid and is doped with iron (III) sulphate.

Claim 43

Dependent Claim 45 words

Process of claim 29, suitable for detecting hydrogen sulfide, wherein said one electrode comprises silver, said polymer is polymethyl metharcylate, and said solvent is propylene carbonate or phosphoric acid-tris-dimethyl amine, and the electrolyte contains as additive potassium hexaflurorphosphate and is doped with iron (III) sulphate.

Claim 44

Dependent Claim 44 words

Process of claim 29, suitable for detecting hydrogen sulfide, wherein the said one electrode comprises silver, said polymer is polymethyl methacrylate, and said solvent is propylene carbonate and the electrolyte contains as additive triethanolamine and acetic acid, and is doped with iron (III) sulphate.

Claim 45

Dependent Claim 42 words

Process of claim 29, suitable for measuring sulfur dioxide, wherein the said one electrode comprises silver, said polymer is polyacrylonitrile, and said solvent is propylene carbonate and the electrolyte contains as additive triethanolamine and acetic acid, and is doped with silver sulphate.

Claim 46

Dependent Claim 45 words

Process of claim 29, suitable for measuring sulfur dioxide, wherein the said one electrode comprises silver, said polymer is polyacrylonitrile, and said solvent is γ-butyrolactone, and the electrolyte contains as additives triethanolamine and acetic acid, and is doped with silver sulphate and iron (III) sulphate.

Claim 47

Dependent Claim 50 words

Process of claim 29, suitable for measuring nitrogen dioxide, wherein one electrode comprises carbon and the other electrode comprises gold or carbon, and said polymer is polymethyl methacrylate, and said solvent is phosphoric acid-tris-dimethyl amine, and the electrolyte contains as additive potassium hexaflurophosphate, and is doped with iron (III) sulphate.

Claim 48

Dependent Claim 39 words

Process of claim 29, suitable for measuring oxygen, wherein one electrode comprises silver and the other electrode comprises lead, said polymer is polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additive triethanolamine and acetic acid.

Claim 49

Dependent Claim 41 words

Process of claim 29, suitable for measuring hydrogen fluoride, wherein one electrode comprises zirconium and the other electrode comprises zirconium or platinum, said polymer is polymethyl methacrylate, and said solvent is propylene carbonate, and the electrolyte contains as additive acetic acid.

Claim 50

Dependent Claim 87 words

Process of claim 29, suitable for measuring chlorine wherein said one electrode comprises platinum, said polymer is polyacrylonitrile, and said solvent is propylene carbonate, and the electrolyte contains as additives tolylic acid and sodium benzoate, and is doped with iron (III) sulphate, and means for polarizing the electrodes during measurement by the application of a voltage in such a way that only a very weak current flows, so that the flow of depolarization current triggered off by the chlorine is a measure of the concentration of chlorine.

Claim 51

Dependent Claim 37 words

Process of claim 28, wherein the gel has an electrical conductivity of at least 10 -5 ohm -1 cm -1 , a dielectric constant of at least 20 and a dipole moment of at least 2.0 Debye.

Claim 52

Dependent Claim 54 words

Process of claim 28, the detector cell comprising a cylinder having a hallow space therein in which there is a ring surrounding the gel electrolyte which is closed off by a measuring electrode on one side which is exposed to the gas to be measured, and by a counter electrode on the other side.

Claim 53

Dependent Claim 65 words

Process of claim 51, wherein the detector is in the form of a throughflow measuring cell having a throughflow element mounted on said cylinder, said throughflow element having an inlet bore for conveying gas to the measuring electrode for passage of gas passed the measuring electrode, and an outlet bore for receiving gas passed by the measuring electrode and discharging the gas from the detector.

Claim 54

Dependent Claim 65 words

Process of claim 28, the detector cell comprising a member having an opening therein, the gel electrolyte being mounted in said opening, the gel electrolyte being provided with a measuring electrode so that a triple phase interface of the gas, measuring electrode and electrolyte is formed on one side of the electrolyte and the other side of the gel electrolyte being provided with a counter-electrode.

Claim 55

Dependent Claim 9 words

Process of claim 53, wherein said opening is cylindrical.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-09-19	1981-03-21	1981-09-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-09-19	1985-03-21	1985-09-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-09-19	1989-03-21	1989-09-20	$7700.00	Window Closed / Lapsed

Electrochemical gas detection

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