Hello! I have a UNIT-T UT210E clamp meter, which I think it has a problem regarding the current measurements.
I will describe the problem below: when I measure current, if the wire is positioned into the center of the clamp (the center marked with the 2 arrows) then it measure 10.16 Aac. But, when I move the wire inside the clamp, then the measured value modifies like this: in the upper part of the clamp the value is 10.5 Aac and in the lower part of the clamp (the closest part to the body of the clamp meter) the value is 9.95 Aac.
I made a calibration of the clamp meter, but the results didn't change.
Meanwhile, if I measure the current using a standard multimeter set to 20Aac then the measured value is 9.9 Aac.

I would like to know if the deviation generated by moving the wire inside the clamp is normal or not ?

LE: in the manual it shows the accuracy on the 20A range as +-(2.5%+8), I understand the +-2.5% but I don't understand how to read the "+8".

 

The high and low results you quote are +/- 5% of 10A. I assume that accuracy of the other meter is > +/- 1%, so it is within spec if the UNIT-T UT210E specified accuracy is +/- 2.5% of full scale.

 

I understand the +-2.5% but I don't understand how to read the "+8".

The ± sign is applied to both 2.5% and 8 of the full scale. The 8 is the number of least significant bits of deviation from the reading. In other words, the UT210E is a 2000 count meter, so the error would then be 8/2000 or 1/250 of the total counts of the selected range. In a scale of 20A, the error given by the 8 would then be ±0.08A.

https://www.designworldonline.com/how-to-determine-digital-multimeter-accuracy/