Insulation resistance Test
httpss://www.youtube.com/watch?v=kFxwxsXi3aI
The multi tester sends a high voltage through one wire and picks up the magnetic fields on the other wire to measure the amount of current that could possibly leak from one wire to another when in normal use .

Perfect just what I was searching for! .
Glad to know it was of a help to you, thanks
Hello! I’m at work surfing around your blog from my new iphone! Just wanted to say I love reading your blog and look forward to all your posts! Carry on the great work!
I spent a great deal of time to locate something like this