Gas detector for detecting nitrogen oxide concentration in gas, has gas concentration detector part with a pair of electrodes, one of which contains platinum and rhodium as principal component

摘要

The gas detector has gas concentration detector part and a pair of electrodes, one of which contains platinum and rhodium as principal component. The detector part detects nitrogen oxide concentration from the oxygen amount formed by reduction decomposition of nitrogen oxide when, predetermined voltage is impressed to the electrode pair. An oxygen pump cell (2) which consists of solid electrolyte body (A) of oxygen ion conductivity and pair of electrodes (21,22), controls oxygen concentration in inner space (31) of the detector. NOx concentration is measured using detector cell consisting of solid electrolyte body (B) and pair of electrodes (61,62). The electrode (22) is exposed to the inner space (31) and electrode (61) is exposed to inner space (32).