| 摘要 |
<p>The output of a direct current power source is divided by a pair of resistances and is applied via a buffer amplifier to any of the electrodes of an electrochemical gas sensor, which is provided with a detection electrode, a counter electrode and a solid electrolyte membrane. The connection point of the other electrode of the electrochemical gas sensor is switched by a switch between a current amplifying circuit and an impedance measuring circuit, and the impedance of the gas sensor is measured. The impedance measuring circuit comprises a resistance one end of which is connected to the switch and an alternate current power source switching the potential of the other end of the resistance between the output potential of the direct current power source and the ground potential. A gas concentration is calculated by storing the humidity dependency and the temperature dependency of the electrochemical gas sensor and correcting the output of the current amplifying circuit on the basis of measured impedance and ambient temperature.</p> |
