That would be a flow meter for welding. It is measuring the volume per minute of c02 being dispensed as opposed to the pressure the gas is exerting. A pressure gauge is cheap, I picked up a replacement for 3 or 4 dollars at Granger Dist. It can't hurt to try.
All the vertical tube floating ball welding flow meters I have ever run across were scaled and calibrated in cu/ft an hour of gas be it Argon, Co2, helium or nitrogen. I have never run across a LPM flow meter unless it was for hospital oxygen use as seen on the walls in hospital rooms or in the ER rooms.
The only liters per/min scale vertical floating ball meters I have ever run across were for medical use like in hospital rooms with scales from .5 to 15 litres per/minute. Timeter Instrument Corporation would be one example.
They are pressure compensated calibrated @ 50 psig 70*F. Model ULO-15.
The Timeter Group. One of these LPM flow gauges were given to me by a hospital maintenance friend for my brewing needs.
Go to
http://www.falconmed.com/items-for-sale.html?page=show_all
Item #6 has 11 Timeter TLO-15 meters for $245, item #7 has 56 for $495.
Your only looking at $22.27 each on the 11 Timeter lot that are new old stock. For used or in excellent condition at only $8.84 each for the 56 Timeter lot.
Do I hear a mass HBT buy in idea for many members to get a great item deal? I already have a brand new one, this would be a great addition for other members. Just remove the quick 1/4 turn inlet disconnect as it has NPT threads in/out. A very high quality meter I must add.
My plan was to use it to on a stone in a exposed glass tube to see the oxygen foam off the stone while transfering wort from the cooled boil keggle to the fermenter adding O2 on the way with a sight window for your pleasure and enjoyment knowing your going to give the yeasties a healthy start. For me just another item to add to the future brewing build project.