OK, reading the question properly now… I suspect it will be something like the pressure guage being manufactured (or specified) by an industrial gases company that uses non-metric measurements, and the flow meter being specified by a medical authority that uses metric.
Sorry 'bout that - that’s the third time in twelve hours that I’ve posted a stupid hasty response (not to mention the stupid pensive ones, naturally) - time for a little break I think.
The tank pressure gauge is usually part of the pressure regulator, which is a generic off-the-shelf device used in many fields. The same regulators are probably used in factories and machine shops, who all prefer English units. In Japan I had to deal with tank pressure gauges marked in kg/cm[sup]2[/sup].
Thanks for the responces. I don’t have any problems understanding PSI or LPM I just found it interesting that they used the two different measurment systems on the same device. My guess has been that folks are just used to using Pounds for measuring pressure and the Medical types like to use the metric Liters for flow and so if it aint broke don’t fix it. :smack: