Multimeter errors

[Abbasis]

I just bought a Southwire clamp meter at a pawn shop for 25 bucks. Only thing I don't like about it is that the red lead shows voltage even when the black lead is still open (not touching anything). What could cause this? Can it be fixed? There were no fuses when I opened it up.

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[hvacrmedic]

I just bought a Southwire clamp meter at a pawn shop for 25 bucks. Only thing I don't like about it is that the red lead shows voltage even when the black lead is still open (not touching anything). What could cause this? Can it be fixed? There were no fuses when I opened it up.

Sent from my LG-US998 using Tapatalk

That’s normal

[JoeyMarquez]

But I can't feel it's normal if I happen to observe this.

[mks]

Floating leads will pick up stray voltage from all sorts of places, particularly from 60Hz AC all around you. Many multimeters have a 60Hz filter that drops most of it, but that one might not. As long as the voltage goes to zero when you short the leads, and you've tested it on a known voltage, I wouldn't worry about it.

[hvacrmedic]

But I can't feel it's normal if I happen to observe this.

Don’t connect only one lead, and your problem will be solved.

[itsiceman]

If it bothers you can you change the range higher so you don't see the mA bouncing around?

[Artrose]

I just bought a Southwire clamp meter at a pawn shop for 25 bucks. Only thing I don't like about it is that the red lead shows voltage even when the black lead is still open (not touching anything). What could cause this? Can it be fixed? There were no fuses when I opened it up.

Sent from my LG-US998 using Tapatalk

And there in lies a relatively common issue with some digital multimeters. Incorrect readings because the operator fails to read the display properly. Mv Millivolts.....V Volts......Ma Milliapms.....A Amps, and so on. If you are aware of this characteristic, it's a non- issue.

In general, higher quality digital meters are more sensitive, and their readouts will have a tendency to float somewhat with their leads disconnected.

In addition, in certain conditions, digital meters can also have a tendency to dampen their readouts, or sometimes be influenced by high electromagnetic fields such as those present in some frequency drives.

Just a couple reasons to carry a higher quality back up analog dinosaur meter.

[ben_john7]

And there in lies a relatively common issue with some digital multimeters. Incorrect readings because the operator fails to read the display properly. Mv Millivolts.....V Volts......Ma Milliapms.....A Amps, and so on. If you are aware of this characteristic, it's a non- issue.

In general, higher quality digital meters are more sensitive, and their readouts will have a tendency to float somewhat with their leads disconnected.

In addition, in certain conditions, digital meters can also have a tendency to dampen their readouts, or sometimes be influenced by high electromagnetic fields such as those present in some frequency drives.

Just a couple reasons to carry a higher quality back up analog dinosaur meter.

Thank you very much for explaining this problem in detail. Honestly, I hadn't heard about it before!

[car46999]

Another way to test that is it just a floating voltage would be to touch and hold the probes together while in voltage measuring mode. This ensures that the voltage potential difference between the probes would be 0V. If it does not read 0V then you should be concerned/investigate.

[orion242]

There were no fuses when I opened it up.

Hope your not using that in the field. Some surgeon will make good money picking pieces of that out of your face.

Normal for a digital meter to pick this up. Get one with loZ mode if it really bothers you. If nothing else, get something with some input protection for that day you forgot your in current mode and take a voltage measurement on a spicy circuit.

[ehsx]

Only buy cat iv safety rated meters.
Can’t find the rating, don’t buy it.
Don’t buy meters that are not auto indexing. You can get false readings if out or range.