I have been playing around with a current clamp that I got for my osciioscope, and I've noticed that the reading I get changes quite a bit if I move the clamp or the wire a little. For instance, I was able to get 9A to show up as around 7A just by twisting the clamp so that it wasn't at a perfect right angle to the wire. It was still fully closed.
Is this normal? How do you know the true reading? Is the highest reading you get get from it always the most accurate it's capable of?
Thanks!
I always find that this is a problem when the clamp does not close evenly and cheaper clamps cannot close evenly. Good high frequency clamps actually have surfaces polished to optical specifications on their split core for consistent performance.