Thread: Air Filter Tests (Finally)

Originally Posted by clubagreenie

So I'll take my 25 years in hydraulic filtration, with my tail between my legs and sod off.

Enjoy

You are by no means the only one suffering from such misconceptions. I have been working in filter R&D for ~15 years, in collaboration with some of the world's biggest filter manufacturers.

There are a LOT of differences between liquid (e.g. hyd oil) filtration and aerosol (e.g. dust) filtration. What you learnt in the hydraulics field does not necessarily carry over.

Did they ever use "arizona dust" for air filtration tests as they did for fluid filtration? Arizona dust being fine particulate matter sourced from certain US test facilities for particular weapons.

Originally Posted by clubagreenie

Did they ever use "arizona dust" for air filtration tests as they did for fluid filtration? Arizona dust being fine particulate matter sourced from certain US test facilities for particular weapons.

Arizona test dust used to be used. However it is considered quite coarse for air filter testing. ISO Fine test dust is usually the standard these days. However (artificial) diesel soot is also used, as this is one of the main "dusts" which filters are exposed to in cities.

PSL - Poly Styrene Latex and DEHS (oil) are commonly used for filter testing as well. They are expensive though, so cannot be used for "dust holding capacity" tests.

We have PSL in drums just standing around in the filter labs.

Originally Posted by clubagreenie

We have PSL in drums just standing around in the filter labs.

Not monodisperse I am sure???

Btw - you need to store it in the fridge. It has a short shelf life and the particle size changes if not stored correctly.

have you by chance tested some of the foam filters on the market like finer filter ect? i used to use these on an expensive piece or grounds equipment before i learnt the hard way even had discussion with there rep ect who basically ****ed in my pocket and told me it was raining after i told him his filters were ****.

I reckon in the correct application using the correct oil they are great.
I have 5 socks which I shove in the top of the snorkel when in the bulldust.
After 18KK with over 5KK dirt , the main filter was clean enough not to change when I got home, instead changing the Finer Filter every 2/3 days.

The "outside" of the filter sock was caked with dirt while the inside was perfectly clean whenever I swapped and cleaned them.

Still I wouldn't use them as the main filter due to the reports like this one and the high possibilty of oil migration to the MAF.
Regards Philip A