| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gas concentration detector, capable of surely excluding external radio wave noise superimposed on wiring unit to attempt, as a result, improving the detecting accuracy of gas concentration. <P>SOLUTION: A sensor controlling circuit board 33 constituting a sensor controlling unit 10 is included in a closed space A of a case 31, that is to be at the ground potential made of electrically conducting material. The sensor controlling circuit board 33 and a wire connecting substrate 34, arranged to the exterior of closed space A are connected electrically through a feed-through capacitor 35 prepared at the wall side of the case. Since the exterior radio wave noise superimposed on the wire connecting substrate 34 is absorbed through the feed-through capacitor 35, influence of noise given to the sensor controlling circuit board 33 can be excluded. <P>COPYRIGHT: (C)2007,JPO&INPIT |
