| 摘要 |
PROBLEM TO BE SOLVED: To prevent the stop of a blower even when at a time of use at a place high in the degree of pollution by stopping the blower on the basis of either one of the outputs of an output lowering detection means and a saturation detection means and the output of an output level judging means. SOLUTION: An output lowering detection means 2 detects the lowering of the output of a gas sensor 1 during the operation of a blower to output the detected output. A saturation detection means 3 detects that the change of the output of the gas sensor is a predetermined value or less during the operation of the blower 7 to output detected output. An output level judging means 4 compares the absolute value of the present output level of the gas sensor 1 during the operation of the blower 7 with a preset predetermined value and the comparison result is outputted. When the absolute value of the output level of the gas sensor is a predetermined value or more, the blower 7 is stopped. |
