> I would argue that the assumption of a distribution of particle sizes is more than?
> justified in any woodworking context.
My point was not that?distribution doesn't exist, but?that it can vary widely, including real-world cases where a comparatively larger filter size will not necessarily result in higher mg/m3, such as fine sanding operations (predominantly sub micron particles) and comparing 1 to 5 micron filters.
Clearly however, for a given particle source, the lower the mg/m3, the better the filtration.? By trying to correlate mg/m3 to filter sizes in any precise way is probably hopeless.?
Trying to correlate filter size to health protection in any precise way is hopeless too.? What matters is how much dust ends up in your lungs, which is a lot more closely correlated to mg/m3 than to filter specs, which by themselves say absolutely nothing about the actual resultant post-filtration dust density, since that depends on other factors like the dust generation rate and the air handling in the space. ? If I pump X quantity of particles thru a filter into a 500 sqft shop, the result is a lot different than pumping it into a 5,000 sqft shop.? And if the shop air handling has say 5 air exchanges per hour, vs. say 15, the results are very different as well.
