JPS6459049A - Gaseous carbon monoxide sensor - Google Patents

Abstract

PURPOSE:To exactly detect only the concn. of gaseous CO by coating the surface of an FET for which an electrode having catalyst activity to gaseous CO and H2 and electrode inert thereto with a proton conductor film and providing an auxiliary electrode thereto. CONSTITUTION:The gaseous CO and H2 as a measuring gas pass the proton conductor film 8 and arrive at the gate electrode 6 of the FET when said gases are introduced into this sensor. The prescribed reaction is then effected on the surface of the gate electrode 6 by the catalyst effect of platinum and the gate electrode 6 attains the negative potential which is deeper with an increase in the concn. of the gaseous CO and H2 is attained. On the other hand, the silver of the source electrode 7 is not sensitive at all to the gaseous CO and H2 and, therefore, the source electrode is kept held at the prescribed potential. Furthermore, a DC power supply 12 is connected between the source electrode 7 and the auxiliary electrode 9, by which the electric signal corresponding only to the concn. of the gaseous CO is taken out of a source region 2 and a drain region 3.