| 摘要 |
<P>PROBLEM TO BE SOLVED: To call attention to, prior to the lifetime of an electrochemical sensor being shortened by freezing in an alarm equipped with the electrochemical sensor which uses water, in order to keep the ionic conductivity of a solid electrolyte membrane. <P>SOLUTION: The concentration of CO is detected in a CO sensor 11 by a microcomputer 10 and an alarm is emitted when the detected concentration of CO becomes preset CO alarm concentration. The thawing weighting coefficient corresponding to thawing rapidity and the freezing weighting coefficient corresponding to freezing rapidity are stored in EEPROM 13 at each temperature section. The ambient temperature of the CO sensor 11 is detected with a thermistor 12. When the ambient temperature is a freezing point or below, the cumulative time is multiplied by the freezing-weighting coefficient at each temperature section; and when the ambient temperature exceeds the freezing point, the cumulative time is multiplied by the thawing-weighting coefficient which is a negative number at each temperature section; and if the sum total (corresponding to the cumulative time difference between the ambient temperature equal to or below the freezing point and that exceeding the freezing point) of the respective multiplied values reaches a predetermined set time threshold, notification of low-temperature freezing is carried out. <P>COPYRIGHT: (C)2011,JPO&INPIT |
