| 摘要 |
PURPOSE:To detect sudden spouting of gas speedily and to perform gas detection in which human life is hardly exposed to danger by providing detection timing points in one cycle. CONSTITUTION:A detecting element 4 to which a couple of heater electrodes 3 and 3 are fixed in one body with a oxide semiconductor is provided. Power sources 1 and 2 heat the couple of heater electrodes 3. A power source 5 detects the resistance between the couple of heater electrodes 3. A timing circuit 7 controls a detection sampling circuit 8 through the power sources 1 and 2 and a pulse frequency multiplying circuit 9. The pulse frequency multiplying circuit 9 allows detection plural times in every cycle T, so speedy response is obtained. A sampling circuit 8 outputs a string of V1, V2...Vn corresponding to detection timing points t1, t2...tn and the string varies with gas concentration. This is outputted as an alarm output sequentially to perform high-precision, speedy detection. |
