GAS SENSOR

摘要

A sensor (140) for detecting a target component in a gas stream comprises a first electrode (144) ; a second electrode (146) ; an active substrate (148) extending between the first and second electrodes, the active substrate being selective to the target component, such that the presence of the target component varies the electrical conductivity of the path between the first and second electrodes. The active substrate preferably comprises a zeolite, in particular zeolite 4A or 13X. A method of detecting a target component in a gas stream comprises contacting the gas stream with an active substrate extending between first and second electrodes; determining the variation in the electrical conductivity of the path between the first and second electrodes; and providing an indication of the presence of the target component in the gas stream. The method is particularly suitable for analyzing the carbon dioxide content of breath exhaled by a subject in the assessment of respiratory function.