Filter micron rating

[98Auburn]

I'm sure this has been addressed already. I have a question on how NAPA and WIX show there bata rating. Lets say for a 1607 NAPA gold filter spec says bata 2/20=17/27. Does this mean at 2 microns a beta rating of 17 or 17 micron at a beta rating of 2?

 

[OldCowboy]

This means at 2 microns the filter is (17-1)/17 or 0.941 or 94.1% efficient and at 20 microns the filter is (27-1)/27 or 0.963 or 96.3% efficient.

 

[ZeeOSix]

Make note of the colors of the numbers in "Beta 2/20=17/27". What this means is the filter is: 50% efficient (beta 2) at 17 microns and 95% efficient (beta 20) at 27 microns The KEY here is to know that red goes with red ... blue goes with blue. First set of numbers (2/20) are the beta numbers. Second set of numbers are the particle micron sizes. WIX and NAPA always use the 2/20 beta numbers (50% and 95% efficiency) in their beta specs.

 

[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?

 

[Sayjac]

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.

 

[OldCowboy]

ZO6 is correct. I had it wrong.

 

[ZeeOSix]

Here's some more info on Beta Ratio and how efficiency is calculated from the Beta Ratio. Beta Ratio = B Efficiency % = (B-1)/B x 100 Here are some Beta Ratio vs. Efficiencies. Beta Ratio -- Efficiency 2 -- 50.0 5 -- 80.0 10 -- 90.0 20 -- 95.0 30 -- 96.7 40 -- 97.5 50 -- 98.0 60 -- 98.3 70 -- 98.6 80 -- 98.8 90 -- 98.9 100 -- 99.0 200 -- 99.5 300 -- 99.7 500 -- 99.8 1000 -- 99.9 sayjac make some good points. Also, if you want to read up more about Beta Ratio, just Google it and you'll find lots of good info.

 

[Ken2]

Plus, you need to know if the ratings are single pass or multi pass. If the filter removes 50% of the 17µ particles every pass, it would remove a much higher percentage with multiple passes of the fluid.

 

[ZeeOSix]

Originally Posted By: Ken2

Plus, you need to know if the ratings are single pass or multi pass. If the filter removes 50% of the 17µ particles every pass, it would remove a much higher percentage with multiple passes of the fluid.

True ... and to add, most filter makers these days test to ISO 4548-12 (I know Purolator does per their website info), which is a multi-pass test. Details below. The ":2000" means this test was established in year 2000. ISO 4548-12:2000 ---------------- Methods of test for full-flow lubricating oil filters for internal combustion engines -- Part 12: Filtration efficiency using particle counting, and contaminant retention capacity. This part of ISO 4548 specifies a multi-pass filtration test with continuous contaminant injection and using the online particle counting method for evaluating the performance of full-flow lubricating oil filters for internal combustion engines. The test procedure determines the contaminant capacity of a filter, its particulate removal characteristics and differential pressure. This test is intended for application to filter elements having a rated flow between 4 l/min and 600 l/min and with an efficiency of less than 99 % at a particle size greater than 10 microns.

 

[98Auburn]

Gentleman, thank you for the info. Another question for the pros. Caterpillar has a line of Ultra High Efficiency engine oil filters that claim to have an absolute rating of 10 micron. In my mind that would be a high quality full flow filter. part #244-4484 What do you think?

 

[ZeeOSix]

Originally Posted By: 98Auburn

Gentleman, thank you for the info. Another question for the pros. Caterpillar has a line of Ultra High Efficiency engine oil filters that claim to have an absolute rating of 10 micron. In my mind that would be a high quality full flow filter. part #244-4484 What do you think?

98.7% efficient at 10 microns is pretty good IMO. Read below. From Technical Service Bulletin 89-5R3a from the Filter Manufacturers Council. "The two most popular reported media ratings are a nominal micron rating (50%) and an absolute micron rating (98.7%). A nominal rating usually means the filter's media can capture a given percentage of particles of a stated size. For example, a filter might be said to have a nominal rating of 50% for particles 10 micrometers in size or larger. An absolute micron rating can be determined by single-pass or multi-pass testing and is usually obtained by passing a test fluid containing particles of a known size through a small, flat sheet of filter media. Any particles that pass through the media are captured and measured. An absolute rating is also expressed in the form of a percentage of the size of particles captured."

 

[98Auburn]

My information was wrong. Less than 15 micron absolute on the engine oil and less than 10 micron on hydrolic and transmission filters. Thats not a bad full flow filter with a bata rating of 75.