| 摘要 |
A residual life indicator for determining the residual life of a filter has a first sample filter with an inlet coupleable to an inlet of the filter whose residual life is to be determined, a second sample filter having an inlet coupleable to an outlet of the filter whose residual life is to be determined, a chemical tracer source selectively coupled to the inlets of the first and second sample filters, and a detector selectively coupled to outlets of the first and second filters. |
