Hantek cc-65 vs regular amp clamp

[ksat44]

Just got a new Hantek cc-65 current clamp and thought I'd compare its readings against an RMS Fluke DMM clamp meter I also have. I used battery charger leads connected to a battery for the test, the Fluke gave me a reading of 0.9-1A and the Hantek, which was set to the 1mv/10ma, gave an RMS on the scope of 197mv, which I imagine equates to 1.97A. Both the Hantek and the Fluke were zeroed out prior to clamping, though with the Hantek woudn't budge from a min value of about -8mv.

Not sure if I'm missing something, but I expected those values to be about the same, not a whole amp different.

Any thoughts?

[Jwillis]

Ya I have the same Hantek CC-65. The lower the current the worse the error gets on DC.
Mine is about 50mA out at a 500mA load. But it gets better as the current go up. At 1A load its about an 18mA error.
DC test done with a series ammeter and a 10 Ohm 10W resistor at  5V and 10V . Compared both ammeter and Hantek CC-65 simultaneously.

Clamp meters are never very accurate anyway so this is not unexpected to me. Considering the price. Comparing two clamp meters will be an even higher error.

I find that that the zero button has to be press a few times to get it zero.But then it starts to climb on its own. Probably due to interference I guess. So zero as best as you can then clamp on a quickly as you can.
These Hantek clamps don't appear to have very good (if any) auto error correction. I imagine more expensive ones might. I don't know.

I don't really use it for low current DC anyway. I got it for checking AC inrush current and ripple current on the oscilloscope. Normally it's not more than a few mA error compared to simulation. It does seem to work better with AC than DC.

[MrAl]

Just got a new Hantek cc-65 current clamp and thought I'd compare its readings against an RMS Fluke DMM clamp meter I also have. I used battery charger leads connected to a battery for the test, the Fluke gave me a reading of 0.9-1A and the Hantek, which was set to the 1mv/10ma, gave an RMS on the scope of 197mv, which I imagine equates to 1.97A. Both the Hantek and the Fluke were zeroed out prior to clamping, though with the Hantek woudn't budge from a min value of about -8mv.

Not sure if I'm missing something, but I expected those values to be about the same, not a whole amp different.

Any thoughts?

Hi there,

Some of these clamps can be very sensitive, very sensitive.  From what I have seen, this requires some extra care when making a measurement.

I have one clamp that is so sensitive that it detects the small magnetic field of the earth.
Since the clamp has a field sensing orientation associated with it, if you even twist the clamp the reading will change.  This means when I zero out the clamp I have to hold it in the exact same orientation when I clamp onto the wire to be measured, otherwise the zero will change even before the measurement is made.  I cannot even twist the clamp a little, because then it senses the magnetic field of the earth a little differently and that messes up the reading of the current in the wire.

So one thing you can try is to hold the clamp steady while you zero it out, and then do not rotate it in any direction as you clamp in on the wire to take the reading.  This requires orientating the clamp into the same plane as it will be when you finally clamp it on the wire when you zero it out.  A translational movement does not seem to matter unless there are other magnetic fields close by like a big magnet or perhaps some metal that has been magnetized.
This works with mine, maybe with yours too.  I was looking to measure currents as low as 10ma.

I did the same thing you did, which was to check the clamp with another reliable meter, except I used a regular wired meter to compare, not another clamp.  If the current measurements are the same or close I assume that the clamp works ok.

[G-son]

I find that that the zero button has to be press a few times to get it zero. But then it starts to climb on its own. Probably due to interference I guess. So zero as best as you can then clamp on a quickly as you can.

I think I've seen someone modify the zero function in one of those clamps on this forum. I think it involved changing to a lower leakage capacitor and a higher input resistor op amp or something along those lines, which would make sense. But as said, it's not a precision instrument in any way, you use it more to see changes than absolute values.

[shapirus]

But as said, it's not a precision instrument in any way, you use it more to see changes than absolute values.

I can second what was said in one of the previous posts: if the instrument is good and if you do not move it after zeroing (critical for DC), then they can be quite precise, even in the 10s of milliamps range, and 100s of milliamps are quite solid. Absolute values, of course. One specific example would be Brymen BM037 which I own. I am sure there are more.

But that being said, I can agree that while they can be precise (and repeatably so), their primary purpose is still not to do precise measurements, because of too many variables that can affect the end result.

[ksat44]

Thanks for all the great replies.

I didn't realize currents at even a not-so-low 1 amp might give the Hantek issues and, frankly, it'd be nice if the thing at least underreported the value instead of what it's doing. The Fluke I mentioned, and even a Klein clamp meter I have, have never given me problems at those levels, so it's kinda disappointing.

Anyway, that being said, I didn't realize you're supposed to keep movement of the Hantek to a minimum after zeroing it out. I'll give that a shot and see if the readings improve any.