Originally Posted By: ZeeOSix
Originally Posted By: goodtimes
Multi pass test uses standard procedures and test dust.
Yes it does, and to add, the ISO 4548-12 multi-pass test is an industry standard that was
developed by an International testing organization, and it's recognized world wide. The test is actually quite involved and requires a pretty complex test rig to perform. You can buy a "turn key" test rig for around $250K.
Originally Posted By: goodtimes
Fram says 98.67% is the limit because the particles are too few to have accurate data any higher than that. Sounds reasonable as most say 99% which is the same thing to two figures. Fram's Ultra could probably say 98.67% @ 18, less than 20, and be the winner.
If Fram is saying that, then how can you believe without any test data (or even with test data because of the Fram bulletin) that someone saying their micro disc filters are 100% at 2u? If you believe what Fram says, no filter maker/tester in the world can claim theirs filters particles above beta 75 because of insignificant test data. So MG just "says" it's so, and you believe them. But if a filter maker says their filter is 99.5 or 99.9% efficient >20 microns you don't believe it because of a 17 year old bulletin Fram wrote - hummm. Seems you're talking out both sides of your mouth.
If you're so confident that Fram's 17 year old bulletin still applies, it has to apply to every filter, and anyone advertising "100% efficiency" at any particle size is false advertising because supposedly the test data can't support such a claim. My position is that's not actually the case, and you must think that too if you somehow believe a micro disc is 100% at 2u just because a company "says so".
Originally Posted By: goodtimes
A size spec doesn't have to be proven, they say the disk has 2 or whatever pores, so that's how it's made. If they tell you your engine has three piston rings, you are going to say no, prove it? If they say your wheel are 16 inches do you go measure to prove it? If MG says 2 micron pores I believe them. They have a patent on it.
My eyes are opened fine, but others are bored with the arguing I'm sure. Go ahead and win now.
Sure a size spec has to be proven ... it's called manufacturing to spec/drawing and then QA to ensure it's built & performs correctly. But in the case of the 2u disc, it should be tested to some recognized test spec to validate the claimed performance spec. You can bet someone measured some 16" wheels (personally I like 19" wheels) that were manufactured to ensure they met the drawing (so tires fit correctly and safely), and also that they were tested for strength, etc to ensure they were meeting other design specs.
And I don't think people reading this stuff are bored at all, they probably like to read some good technical debates once and awhile.
Very good post ZeeOSix. What you are saying makes perfect sense.