| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a gas alarm system capable of accurately detecting degradation of a contact combustion type gas sensor.SOLUTION: A comparison element 24 of a contact combustion type gas sensor 2 is provided with a cap part 242, and poisoning substance P is prevented from being adhered. When the poisoning substance P is adhered to a detection element 23, the calorific capacity of the detection element 23 rises, the temperature thereof is lowered, thus reducing a resistance value RS, and an air baseΔV which is a neutral point potential difference of a bridge circuit 20 becomes small. A CPU 31 determines degradation on the basis of the air baseΔV, and thus the degradation can be determined when the sensitivity of the contact combustion type gas sensor 2 is reduced due to adhesion of the poisoning substance P. Thereby, the degradation of the contact combustion type gas sensor 2 can be accurately detected.</p> |
