Where I work, we have to do this in our central tool rooms. Everytime a tool is checked out, the tool room staff does a visual inspection, and then plugs the tool into a piece of test equipment that tests the insulation and the ground continuity. Once per quarter, I have to check the ground continuity on the tools, and log them into a log book. Before, our Safety dept. told the tool room staff to just plug the tools and ext. cords into a GFCI receptacle before issue, but I bought them a tool tester that performs a hi-pot test and checks the ground's continuity all in one shot.
