UNI-T UT202A+ measuring problem ?!

[123mmm]

Hello! I have a UNI-T UT202A+ clamp meter. When measuring AC current, I noticed the following: If placing the measured electric conductor right in the geometrical center of the clamp, then the clamp meter shows 4.720A. But, if placing the conductor in the upper side of the clamp, then it shows 4.680A. Also, if moving the conductor to the down part of the clamp (the most close to the body of the clamp meter) then it shows 4.490A.

Please have a look at the image:


In the clamp meter's manual, it is mentioned:



It is normal to appear this difference between the measured values ?

 

[rjenkinsgb]

It's not unusual.

Clamp meters work based on the magnetic field produced by the cable & different positions or to some extent proximity to other current-carrying cables or ferrous items that can affect the magnetic field can influence the readings.

There could also be a bit of dirt or glue / varnish etc. on the faces of the jaws where they meet, causing and airgap and affecting the sensitivity in that area.