| 摘要 |
<p>An air filter assembly has a fan, pre-filter, a main filter, and a control means which generates signals to the user as to when the pre-filter and the main filter should be replaced, individually. The control means detects clogging occurrences of the pre-filter (N), and end of useful life occurrences of the pre-filter (M). The control means detects when the main filter should be replaced based on a counting value ("Z") in accordance with following formula: Z = N + C × M . where ("C") is a correction factor. The control means also detects a main filter replacement condition based on cumulative operating time of main filter. The main filter can have a fuse that is blown when the main filter should be replaced.</p> |
