Surely, most who read this article will find the information rather obscure, but for any brewer who uses a PSI meter on an O2 tank with a sintered stone, it was very difficult to find any info related to this on the Internet. So here we go:
For those of us who use O2 tanks with a regulator that displays PSI rather than flow, it can be a dubious battle to figure out proper air flow. One way to do this is to set the O2 regulator to a set PSI, attach the .5 micron sintered stone to the tube, affix a milk bag (1 litre) to the stone, start flowing the O2, and time how long it takes to fill the milk bag.
For our system, we found that setting our PSI regulator to 15 will fill a milk bag from crumpled to plump in exactly a minute. Using a .5 micron sintered stone, this flow rate will saturate our wort with ~8-10ppm of 02 (optimal) in one minute.