Always important for me, but this post is for inspectors. I got a call from a builder that a gfi rec. @ panel showed 'false ground' on the inspectors $280 tester. Over the phone I told the builder what to look for, to make sure I had done it right and all looked good. Builder calls insp, who shows up later to say that after reading the tester's manual (Ideal) that it has problems within 15' of the panel. 2 things; know your equipment, and what's the use of a tester like that?

The test the inspector was doing was to check for neutral to ground connections.

The tester does this by measuring the resistance between neutral and ground.

As neutral and ground are tied together at the panel having false readings once you get near the panel are unavoidable.

But I do agree, the inspector should have been more familiar with the equipment before using.