CIRCUIT FOR CONTROLLING CARBON MONOXIDE SENSOR

摘要

PROBLEM TO BE SOLVED: To accurately detect carbon monoxide even if the zero point of sensor output fluctuates with the time elapsed in the control circuit of the carbon monoxide sensor of voltage output. SOLUTION: The control circuit successively compares an output voltage after the voltage between electrodes 2 and 3 being installed on a solid electrolyte plate 1 is amplified by an amplifier 8 with the output of a storage voltage- outputting means 12 by a voltage comparator 9 according to the instruction of a storage instruction switch 11, stores the matched voltage by a storage means 10, and outputs a voltage value corresponding to a value being stored by the storage means 10 using the storage voltage-outputting means 12. The output of the storage voltage-outputting means 12 cannot be updated until the storage instruction switch 11 is pressed and continues to be retained as a voltage that becomes a zero-point voltage when the concentration of carbon monoxide is detected.