| 摘要 |
<p>PURPOSE:To obtain a long-life detecting device which has small power consumption by detecting flammable gas when the flammable gas is admitted, and turning on the main power source of the whole device and measuring object gas concentration. CONSTITUTION:When the flammable gas is admitted to a 2nd infrared detector 2 through a gas intake pipe 4, a detection signal is generated. This signal is sent to an electric feeding control part 100 through a detecting circuit 105. Consequently, the main power source 101 is driven to supply electric power. Consequently, the infrared light source emits an infrared ray, and the detector detects the infrared ray from the light source 3 and applies its detection signal to a comparing circuit 106 through the circuit 105. An optical filter 12, on the other hand, passes only part of the infrared ray from the light source 3 which has 3.3mum when the gas to be detected is gaseous methane. The transmitted infrared ray is detected 1 and its detection signal is inputted to the circuit 106 through a detecting circuit 102. The circuit 106 calculates the difference between both signals to obtain a signal having a level proportional to the gas concentration.</p> |
