摘要 |
A sensor and method for detecting a target substance, particularly CO2, in a gas stream comprises a sensing element disposed to be exposed to the gas stream, the sensing element comprising a working electrode; a counter electrode; and a solid electrolyte precursor extending between and in contact with the working and counter electrodes; whereby the gas stream may be caused to impinge upon the solid electrolyte precursor such that water vapour in the gas stream at least partially hydrates the precursor to form an electrolyte in electrical contact with the working electrode and the counter electrode. The method measures the current flowing between the working counter electrodes as a result of the applied potential; and determines, from the measured current flow, an indication of the concentration of the target substance. The sensor and method are particularly suitable for analyzing tidal carbon dioxide concentrations in the exhaled breath of a person.
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