| 摘要 |
<p>PROBLEM TO BE SOLVED: To urge exchange of a filter by sounding an alarm since a battery life is decreased due to the increase of the number of regeneration treatment times when a time interval from regeneration treatment of a filter to next regeneration treatment owing to choking of the filter is gradually shortened. SOLUTION: A time interval from regeneration of a filter 3 to next regeneration is measured and held by a timer circuit in a control unit 7 each time, and an average of values equivalent to the number K of times is calculated by a computing circuit 21. The average value and a set value are compared with each other and when the average value is lower than the set value, it is decided that choking of the filter 3 occurs. By outputting indication from the computing circuit 21, a filter exchange timing display lamp 14 is lighted ON and an operator is urged to exchange the filter 3.</p> |
