Any regular electronic voltmeter can be set on volts scale and connected between the power lead and ground lead. You could do it at the power supply or at the feeder and the ground. Amperage is pretty hard to measure unless you have a very heavy ammeter that can take the load. To measure feed run the wire out for six seconds, measure and multiply by ten for your rate per minute. Sometimes dials are marked with the feed per minute and on later models it is given via a digital readout on the feeder. One on Miller's articles gives conversion from feed rate to amperage for different wire diameters. I will look around again for it. Randy
Getting into MIG welding. However, my notebook full of arbitrary settings for different machines like "2-4,8","1-3,2~1/3", "6A,7" and so on (in my own notation, this is "(,)")
Problem is, if machines are different, is "2-2,7" the same condition as "6A,7", for instance?
How do you measure Volts and Amps on a MIG welder? And can you measure wire feed speed in say metres-per-second or inches-per-minute?
Simple but 100% effective. Will work for every machine I now encounter.
Overlooked this - that no machine I now meet and most participants on the group meet has a "soft-start" - so can do this. Bend the wire over at the tip by 90deg, pull the trigger for 6seconds and measure from the contactor to the bend.
Randy - reason I overlooked this - when doing my welding research in the 90's most of the machines I met were "top of the range" - very expensive machines - with "soft start". So that technique wouldn't work.
Explanation - with "soft start" the wire feeds slowly until an current is drawn (the arc starts) whereupon the wire-feed gets going at its set value. Makes starting your weld easier. So when you pull the trigger with the torch pointing up in the air, the wire feed you see is much slower than the feed rate when welding.
Guess "reactive filter" helmets, where you can see what you are doing as you line up the torch, make the soft-start less important these days(?).
I'll go looking up the wire-feed-speed to amps chart - many thanks.
Something that many people don't realise is that amperage on wire feed constant voltage machines can vary widely. Increasing or decreasing stickout can change amperage down or up 25 amps from the ideal stickout. When one gets up into the higher amperages this can make a significant difference in the weld bead. The amperage is only an approximation. Each operator will be using the same settings and yet be running a different amperage depending on stickout used. Most weld procedures written up for critical welding will include the stickout to be used by the operator. Randy
This - the Miller manual you mention - was really interesting for me. It suggests what might be called a "current-lead" method to find your settings on the MIG welding machine -- works because:
for MIG welding you want the 1Amp-per-0.001inch of thickness used for eg. TIG welding
you can estimate current from wire-feed-speed given the wire diameter.
you can measure wire-feed-speed easily
I've been shown a voltage-lead method which is much more trial-and-error.
Appended is Miller's current-lead method, as best I can transcribe it into text without their diagrams: