MM251 Welding Amps--Hobart Expert

[Mike W]

I have a Fluke clamp on probe that will work on AC or DC. It plugs into a DVM. One millivolt equals one amp.

[Dave Haak]

Aaron & Roger,

Thanks.

Dave

Hall effect sensor makes it AC/DC clamp on meter.

AC clamp on meters have coil of wire that is held close to wire carrying the AC electricity you want to measure. The AC causes a magnetic field around the wire that changes 120 times a second which induces propotional electrical current in the coil that is measured by the meter.

Autoranging is different feature. So easy to do with digital meter should be included as costs more for extra switch or jacks for manual ranges.

[Al T.]

I think I'll get one, you can never have too many tools!

[Dave Haak]

Roger,

Thanks. I stumbled through the link. A little over my head. Is the bottom line that by using the "Hall Effect", it is autoranging?

Thanks.

Dave

Originally posted by Dave Haak
Aaron,

Is it autoranging? I don't see it mentioned in the spec. It says it comes with a thermocouple adapter. Do you have to buy a separate temerature probe or is it included? I don't see it pictured.

Thanks.

Dave

Thermocouple probe included.

AC DC clamp amp meters use hall effect sensor that measures magnetic field strenth. A Hall Effect sensor uses a semiconductor material through which a constant voltage source forces a constant bias current to flow. If the biased Hall sensor is placed in a magnetic field oriented at right angles to the Hall current, the voltage output varies in direct proportion to the strength of the magnetic field.

http://www.sears.com/sr/product/details/productdetails.jsp?BV_SessionID=@@@@0095158501.1061377703@@@@&BV_EngineID=ccekadcjefkhdekcehgcemgdffmdflg.0&vertical=SEARS&prod_id=03482353000&fromAuto=null&bidsite=CRAFT

http://www.wikipedia.org/wiki/Hall_effect

[Dave Haak]

Aaron,

Is it autoranging? I don't see it mentioned in the spec. It says it comes with a thermocouple adapter. Do you have to buy a separate temerature probe or is it included? I don't see it pictured.

Thanks.

Dave

[widetrackman]

Originally posted by aweaver
Dan,

Gee, I just bought an AC/DC clampmeter about a month ago.

Check this out:

http://www.sears.com/sr/product/summary/productsummary.jsp?BV_SessionID=@@@@1720960440.1061322094@@@@&BV_EngineID=ccekadcjefkhdekcehgcemgdffmdflg.0&vertical=SEARS&bidsite=CRAFT&pid=03482353000

Aaron

Aaron , does this meter have the hold feature? also do you just clamp it anywhere over the gun cable? thanks again

[Dan]

Thanks guys. Looks like I really need to up date my electrical knowledge doesn t it. A clamp on amp meter is definately a much easier approach then what I assumed I was going to have to do. Hopefully my ignorance to this newer technology benefits others too.

Aaron, it looks like I owe you a free welding lesson now.

[Al T.]

Dan,
You used to be right, in the last few years the price of true dc clamp-on ameters has really come down. 10 years ago I purchased a clamp-on Fluke adapter to measure DC current. Cost $280. It uses a hall-effect transistor technology to measure electron flow. Its not as accurate as the one Aaron bought, but it was all that was available at the time.

[dseman]

clamp-on current meters

Dan,

Actually, clamp-on current meters are available which will measure both ac or dc current. I'm sure fluke makes them as well as others such as the extech models below:

ex-38389 600amp ac/dc current, true rms,voltage,resistance, capacitance, temp. +/- 3.5% basic accuracy. $99

ex-38095F 1000amp ac/dc current, true
rms. voltage, resistance, temp. +/1.5%
accuracy. $179

-dseman

[Dan]

Originally posted by aweaver


Dan,

Why not just use a clamp on ammeter? You can get a meter with peak-hold, place it over the work clamp's cable, and weld away. When your done, check to see your peak current.

Aaron

Aaron, a clamp on amp meter only works for AC. As you know our MIG machines output DC.

[Hobart Expert Kevin]

Rocky D,
Maybe I'll get to L.A. for one of our service schools next year.

Dan,
You will not void your warranty by hooking an amp meter set-up to your machine as long as you don't start doing some creative wiring inside the unit.

Kevin

[email protected]

[Dan]

Kevin

I ve been thinking about purchasing a 300 amp shunt and amp meter and setting this up in a seperate box that allows me to hook the amp meter up to any of my machines. My question is will hooking this amp meter up to my machines void the warranty?

Thanks for the invite Kevin, but I'll have to wait till you can get to L.A. or San Diego...that's a 942.65 miles and 15hrs 24min round trip for me. Intestate 5 between L.A. and San Francisco is the most boring piece of asphalt on the planet, too. If I had Franz's money, I'd fly, but time won't permit, either.