From reading this board and several threads I've thought that the 'nominal' micron rating was a vague spec. I was under the impression that it was 'supposed to mean' at 50%, yet there have been several threads here where that didn't appear to be the case. Someone here once concluded based on Wix or some other filter spec that it could mean any percent. Based on the definition explained by Cummins engine I'm now inclined to agree with that conclusion.
"Nominal micron rating is just a commercial trick for all efficiencies lower than 98.6%, meaning that for the same micron rating (for ex. 10 µ) in the case of nominal rating, not all particles will be captured in the filter as in the case of absolute micron rating. "
Cummins filtration FAQ.
It seems that similar to the old single pass efficiency test spec the term nominal rating is an unreliable and outdated spec. So, the absolute rating (98.6%) is really the only reliable term.
Thoughts?
"Nominal micron rating is just a commercial trick for all efficiencies lower than 98.6%, meaning that for the same micron rating (for ex. 10 µ) in the case of nominal rating, not all particles will be captured in the filter as in the case of absolute micron rating. "
Cummins filtration FAQ.
It seems that similar to the old single pass efficiency test spec the term nominal rating is an unreliable and outdated spec. So, the absolute rating (98.6%) is really the only reliable term.
Thoughts?