MM251 Welding Amps--Hobart Expert

[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.

[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.

[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

[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

[Roger]

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]

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

[Al T.]

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

[Roger]

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.

[Dave Haak]

Aaron & Roger,

Thanks.

Dave

[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.