| 摘要 |
PROBLEM TO BE SOLVED: To determine whether a circuit for detecting an ambient temperature of a detection object atmosphere is normal or abnormal.SOLUTION: A combustible gas detector 1 performs control to change over energization state to a heat element 12 for each 100 ms so as to alternately change over the temperature of the heat element 12 between a preset first setup temperature (a high temperature), and a second setup temperature (a low temperature) that is set lower than the first setup temperature. A temperature adjustment circuit 32 uses a temperature measuring resistor 17 to output a temperature voltage VT representing a voltage value corresponding to the ambient temperature. When a difference between an average value VTHav of temperature voltages at the high temperature and an average value VTLav of temperature voltages at the low temperature is less than a preset abnormality determination voltage, the combustible gas detector 1 determines that abnormality occurs in the temperature adjustment circuit 32.SELECTED DRAWING: Figure 1 |
