Originally Posted By: 98Auburn
Zee, I understand what you mean. I was hoping for the sake of filter efficiency the ratings would be the way Cowboy posted. Can anyone else confirm what Zee is saying?
ZO6 is the beta man, I learned it from him and it's exactly the way he has it written.
Just to add to it, if the first number is 2, think 1 over 2 or 1/2 = 50%, then subtract that from 100%, =50% efficient at the corresponding micron level. In the example above @ 17um. The 20 would be 1/20 or 5%, subtract from 100% = 95% @ 27um(ex. above). Another way to think of it is, the example media allows 5% of 27um particle size through.
Imo, ZO's explantion using color seems an easy way to understand the beta #'s and how to decipher them.