What can you tell me about these two beta ratios?

[rcy]

What is the difference between these two filter's beta ratios? Is one better than the other?

#1 - 2/20=6/19

#2 - 2/20=22/40

Thanks.

 

[Tempest]

#1 is MUCH better.

A good article on Beta Ratios: Here

 

[Bill Kapaun]

A different link to Beta-

http://www.filtercouncil.org/techdata/tsbs/89-5R3.html

 

[westwind999]

I had some similar questions and I find most of the articles difficult to understand. From what I gather the 2/20 thing is the minimum size particle it will filter 50%/95% of the time in microns. In your case the first one would get 6micron particles 50% of the time and 19micron particles 95% of the time. As you can see the first one traps particles more often at less than half the size of the second one.

 

[Gary Allan]

Rewording that, westwind .... Beta6=2 means that 50% of the particles of 6um or bigger are filtered. Beta19=20 means that 95% of the particles 19um and larger.

To fill in the unspoken part of it (that most people miss) ...

50% of the particles 6um and various levels of LARGER PARTICLES get through

5% of 19um and various lower levels of larger particles get through.

That is, if the beta ratio for 10um particles was listed ..it would be somewhat higher then Beta2 ..if the beta ratio was listed for 30um particles it would be higher then beta20

A minor distinction in view..but one that's kinda skipped over. It's not like ONLY 6um particles are getting through ...they're just the ones getting through at the 5% rate. Larger particles are getting through at 4%, 3%, 2%, 1%, and fractional percentages.

 

[westwind999]

Thanks for the info. I guess the understanding is that the filter media doesn't have perfect size holes in it to let the oil through so sometimes a larger particle will find a larger hole and slip through. Likewise a smaller particle might get caught if it happens on a more dense part of the media. Interesting how it seems to account better for a real situation.

So realistically how big of particle would cause damage? Obviously particles are bad but what sort of magnitude are we talking about?

 

[Gary Allan]

Well, I'd say that you can improve the "managed damage" with filtration in the 10-15um range or lower. Obviously, the 30-35+ filtration does a fair job of limiting damage over the normal (current) life cycle of many millions of engines. The difference will be in the condition at any point along the way ..that may or may not show itself in advanced years.