| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gas concentration measuring apparatus capable of accurately measuring the concentration of gas to be measured in the ambient atmosphere through the use of an electrochemical gas sensor, even if radio waves exist in the surroundings. <P>SOLUTION: A short-circuit current, flowing from a counter electrode 32 to a detection electrode 31 due to the movement of electrons generated at the detection electrode 31 according to the concentration of CO gas in the ambient atmosphere of the electrochemical CO sensor 1 to the counter electrode 32, is converted into CO concentration signals of a voltage value, corresponding to the concentration of CO gas in the ambient atmosphere of the electrochemical CO sensor 1. The CO concentration signals are amplified by an operational amplifier AMP, of which the positive-phase input terminal is connected to the detection electrode 31, of which a reversed-phase input terminal is connected to the counter electrode 32, and which operates on a base voltage, supplied from a base voltage generating circuit 30 for the positive-phase input terminal in a CO alarm. The wire between the counter electrode 32 and the reversed-phase input terminal is grounded via a capacitor C, and inductors L3 and L4 are interposed in between the detection electrode 31 and the positive-phase input terminal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
