Nominal Micron??

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I am looking at the specs for two filters. One says Nominal Micron=30. The other says Nominal Micron=19. I assume the one with the 19 is the better filter, but, what does Nominal Micron mean, what is it telling me?
 
"nominal" is a statistical term that, in layman's term, equivalent to something like "on an average".

So, in other words: even though you go for "nominal micron=19", it just means to for the most part, 19u particles get dealt with, with a smaller possibility of anything smaller/larger slipping through the process.

Q.
 
realize that 19 isnt necessarily better than 30.

One might trap more particles at first, but will flow far less as a cake is develloped. One might let more fines through, but will keep flowing after a cake is formed.

Its an engineering tradeoff, and Id likely go with the 30, particularly if going for a longer OCI.

JMH
 
In the automotive filter lexicon (sorry-no link
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) your nominal rating is for a single pass test. Apparently repeatability is a problem with this rating. The multipass test is more reliable in indicating filter efficiency.

That's why you'll see .....
2/20=14/31 (multipass)
Nominal Micron Rating: 20
 
Gary, thanks for that explanation, I think I'm starting to understand this and Beta Ratios. I have 2 questions.

First, is it accurate to say with all other things equal, a Beta Ratio of 2/20=15/22 is better filtration than 2/20=22/40?

Second, does Amsoil publish this data for the EaO filter? I ask because both the EaO20 and EaO12 fit my Subaru and I wonder if one has better filtration.
 
Quote:
First, is it accurate to say with all other things equal, a Beta Ratio of 2/20=15/22 is better filtration than 2/20=22/40?


Yes. That would be

50% of the 15um (and larger) particles were filtered and 95% of the 22um (or greater) particles were filtered..

vs.

50% of the 22um (or larger) and 95% of the 40um (or larger).

Quote:
Second, does Amsoil publish this data for the EaO filter? I ask because both the EaO20 and EaO12 fit my Subaru and I wonder if one has better filtration.


Not as such ..Wix appears to have this jewel of a spec trump card in readily available data.

Amsoil's EaO is rated at 15um Absolute ..which would be a Beta 75

(74/75 = 98.7%)

In case you haven't gotten the beta primer, regardless of how it's expressed, the beta number is figured beta-1/beta = the % of the micro size.

So the 2/20 = 15/30 (for example in the case of Wix) would be

2-1(or 1)/2 = 1/2 = 50%
20-1 (or 19)/20= 19/20= 95%

You may find it published in a couple of ways depending on if it's in a table or just individually listed - but, typically, you won't see a beta 13 ...while you will see a Beta 75 for a 13um particle. That is beta numbers usually fall into sensible ranges ..while the particles that they filter tend to be all over the place. I have seen exceptions, but not in automotive filtration and even rarely in hydraulics ..but that just may be do to my depth of exposure (which is probably deep for "novice class" exploration - but there's surely much more for the insiders).

An old Greshen filter I have has it listed like this:

Beta10=2
Beta20=20
Beta22=75

This would be (sorta) counter to the way Wix lists it ..but since you know there should be at least a 50% notation ..and you know that 75 is the absolute notation ..you can back figure that the "Beta#" is the size and the = X is the efficiency rating.
 
Originally Posted By: Gary Allan
Amsoil's EaO is rated at 15um Absolute ..which would be a Beta 75

(74/75 = 98.7%)
So is that the same rating for all the EaO's? If they do filter the same, and since there are no clearance issues, am I better off with the slightly larger volume of the EaO20 than the EaO12?
 
Originally Posted By: Lorenzo
Originally Posted By: Gary Allan
Amsoil's EaO is rated at 15um Absolute ..which would be a Beta 75

(74/75 = 98.7%)
So is that the same rating for all the EaO's? If they do filter the same, and since there are no clearance issues, am I better off with the slightly larger volume of the EaO20 than the EaO12?


Straight from the site:

Absolute Efficiency
AMSOIL Ea Oil Filters have the best efficiency rating in the industry. EaO Filters provide a filtering efficiency in accordance with industry standard ISO 4548-12 of 98.7 percent at 15 microns, while competitive filters containing conventional cellulose medias range from 40 to 80 percent efficiency


I see no reason (off hand) why you couldn't.
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please see my post above... there are 'ratings' and then there are realities of how filtration works.

JMH
 
Originally Posted By: JHZR2
please see my post above... there are 'ratings' and then there are realities of how filtration works.

JMH


So, unless we do a particulate test on the PureONE (which has as LOT of filter media) we really don't know.

Similar to the test done by somebody on here with an EaO and the Mobil 1 filter where the Mobil 1's particulate count was substantially better and caused a bit of a stir.....

A similar test would have to be run on the PureONE to really gauge how efficient it is.
 
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Originally Posted By: OVERK1LL
How does this compare to the PureONE's 99.9% rating?


At some unpublished level. Every filter is 99.9% efficient at 500um. I haven't bought the new PureOne ..but the box sitting right here next to me boast of 98% on the multipass test ..with no mention of the micron rating.

I do regard PureOne as a good filter value.

While I'll agree with JHZR2 in, what I call, the "filtration triangle" there are some differences in efficiency and holding capacity with different medias.
 
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