Gas Flow Meter - Conversion Rates

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I have a rather long intro so bear with me. But the final question relates to the conversion factor to use for an Air flow meter when running Argon.I have an AHP TIG welder with a float type (ball in tube) flow meter. I decided to check for leaks just to make sure I had none. As an FYI - there does not appear to be any significant leak from the tank to the welder since the pressure gauge does not drop to zero after more than 24 hours after I shut off the tank valve and the welder is off. But I also wanted to check the welder gas input to torch output connections.I purchased a low cost float type flow checker that was marked for Argon in L/min. When the checker was attached to the torch it read 16-18 CFH (converted from L/min) when the welder flow gauge was reading 20 CFH. So I figured I had a leak. After a lot of soapy water none was found. So I removed the hose from the welder and checked flow there - same result as the torch output. Now I questioned whether my gauge was accurate. So I bought a Dwyer RMB-52 flow meter that is calibrated for Air flow rates of 5 - 50 SCFH. When connected to the tank hose the Dwyer read 16 CFH on its Air scale (still with the AHP flow gauge was set to 20 CFH Argon). Now the question - what conversion factor to use going from Air to Argon on the Dwyer meter. Theoretically I should divide the Dwyer Air reading by 1.18 since the specific gravity of Argon is 1.44 (versus 1.0 for Air). That would mean the Dwyer reads 13.6 CFH Argon versus 20 on AHP. To get the meters to agree I should multiply the Dwyer Air reading by 1.18 instead of divide.Sources on the internet are also confusing - some say multiply by 1.18 others say divide by 1.18.Any thoughts?
Reply:Ditch the metric lpmflowgauge and buy a good CFH flowmeter. I know it will cost you some $30  but it is a lifetime purchase that will pay back your investment quickly, not to mention peace of mind. I get mine at netwelding.comWeld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Gas flowmeter conversion - see question # 2 here:  http://www.dwyer-inst.com/Product/Fl...AOcw#questionsA specific gravity correction factor will need to be considered when monitoring other gases with a meter calibrated for air. The correction factor equation is as follows: Q2=Q1 x sqrt (1/S.G.) Where: Q1= Observed Flowmeter reading Q2= Standard Flow Corrected for Specific Gravity 1= Specific Gravity of Air or Water S.G.= Specific Gravity of media being used in flowmeter originally calibrated for air or water.This equation can be found in the beginning of the Flow section in the catalog. Alternatively, special ranges and scales can be provided; for specific information please contact our customer service department.For further information, see our "Tech & Specs" Video Blog: Fix your Flow... Specific Gravity and Pressure Corrections for Variable Area Flowmeters (Episode 4), in Dwyer's Video Library. See page 123 of their catalog for a graph and the formula:  http://www.dwyer-inst.com/New2016Catalog/I ran the numbers using 1.38 as the specific gravity of Argon.  Looks like 16 CFH air = 13.6 CFH Argon."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by OldendumGas flowmeter conversion - see question # 2 here:  http://www.dwyer-inst.com/Product/Fl...AOcw#questionsA specific gravity correction factor will need to be considered when monitoring other gases with a meter calibrated for air. The correction factor equation is as follows: Q2=Q1 x sqrt (1/S.G.) Where: Q1= Observed Flowmeter reading Q2= Standard Flow Corrected for Specific Gravity 1= Specific Gravity of Air or Water S.G.= Specific Gravity of media being used in flowmeter originally calibrated for air or water.This equation can be found in the beginning of the Flow section in the catalog. Alternatively, special ranges and scales can be provided; for specific information please contact our customer service department.For further information, see our "Tech & Specs" Video Blog: Fix your Flow... Specific Gravity and Pressure Corrections for Variable Area Flowmeters (Episode 4), in Dwyer's Video Library. See page 123 of their catalog for a graph and the formula:  http://www.dwyer-inst.com/New2016Catalog/I ran the numbers using 1.38 as the specific gravity of Argon.  Looks like 16 CFH air = 13.6 CFH Argon.
Reply:Sounds like a plan."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder