- Sep 28, 2002
Well, you can't ..but you can see the general condition of the filter. Since you don't see any physical degradation, you can reason that you haven't subjected it to any other operational insult except loading. I've personally subjected a 9k old filter to testing using differential pressure gauges and found that it was still quite serviceable. Now if you pulled on apart and found that lots of moisture had congealed on the media ..etc..etc..then you may have had it in service longer than you would like.