Testing Amps or Volts with Clamp type meter?

[twinpoint]

I have an AC/DC clamp on type Amp/Volt Meter and need to make sure a welder who is taking a test has his settings in the range to meet the WPS. He is using SMAW. I clamp the meter around the welder cable near the stinger and the readings I get are REALLY low. What am I doing wrong?

 

[gtaw]

It would be helpful if we knew whether you were reading AC or DC and if you had the meter set to read the appropriate type of current. Likewise, were you reading voltage or current? Using a clamp-on meter I would assume you are trying to determine the current, but it is something you need to verify. Is your test instrument set to read the specific parameter you are trying to measure?

Best regards - Al

 

[MikeHalloran]

An AC clamp-on ammeter will give a somewhat useful reading on DC current, >as the current is switched on<, for a few milliseconds. It might even be somewhere near the real current, if the meter has a peak hold function that's on at the time.

DC clamp-on ammeters used to cost a LOT more money; nowadays I don't know if they do or not.

Can you measure the voltage across a shunt instead?



Mike Halloran
Pembroke Pines, FL, USA

 

[stanweld]

The SMAW process uses a constant current power supply. Current can be readily measured. The voltage is a predominatly a function of current and electrode diameter and arc length. It cannot be set by the welder. Measure the voltage seperately across the terminals at the power supply. If the electrical leads are short, the measurement will be reasonably accurate.

By the way, how low were the values and which electrode classification was being used? You may have a more accurate reading than you think.

 

[twinpoint]

Thank you for all the input - very helpful. The low-end meter I used was only AC amps and not RMS.

I posted the same question on weldingweb.com and what I came up with is that I need a meter that reads DC amps and is an RMS ammeter.

I looked high and low for a reasonably priced meter that had all the features I need and ended up buying a new Klein CL2000 for $89 on ebay. Also someone recommended this sears ammeter

http://www.sears.com/craftsman-prof...p-03473756000P?prdNo=1&blockNo=1&blockType=G1