| 摘要 |
PROBLEM TO BE SOLVED: To easily detect hydrogen gas, having a varied concentration depending on blowing timing of inspection gas, and to prevent incorrect operation in an inspection mode to inspect a gas leakage alarm function for city gas alarm by blowing the inspection gas extracted from a lighter etc. upon a semiconductor gas sensor 10 of a gas alarm unit 1. SOLUTION: By the control of the heater cycle of the semiconductor gas sensor 10 by a microcomputer 11, the city gas alarm is issued using hydrogen concentration and CO concentration detected at a hydrogen detection point and a CO detection point in a heater cycle. An alarm level to decide hydrogen concentration alarm is set to a lower concentration level. The city gas alarm is issued if the hydrogen concentration reaches the alarm level or higher at the previous hydrogen detection point or the present hydrogen detection point, under the condition that the CO concentration reaches a CO lower-concentration alarm level or higher at the CO detection point. COPYRIGHT: (C)2010,JPO&INPIT
|
