Tim Wescott wrote:
When you see something like "3.2CFM at 60PSI", where are the cubic feet
measured?

Does that mean that the compressor is putting 3.2 CFM of air at 5x
atmospheric pressure into the tank (and hence that you'll get 16 CFM of
air out the hose, once it's relaxed back to atmospheric), or does that
mean that you will be able to inflate 3.2 one-cubic-foot balloons per
minute with the air that comes out of the hose?

I assume that it's the latter, but I want to check.


All depends on what company made it...
If it's a Sears then 3.2 CFM is what it would produce wired for 440
turning about 10K rpms and measured just before it blows apart from the
stress...

If it's a good unit then it should mean the airflow at the exhaust port
of the compressor head prior to any fittings, with the compressor
running at specific rpms and usually measured with NO air inlet filtration.

Same method is used for a water pump except you have to add in any
incoming pressure/vacuum as well.

--
Steve W.