Last time, I forgot to mention one thing you’ll want to have to go with the clamp-on meter–a line splitter for plugging in to standard 15-amp outlets.

What does this do?  It breaks out the line wire to where you can clamp around it by itself.  Without getting too far into the details, the clamp-on ammeter is going to show you net current through the clamp-.  If you just clamp it around a power cord, it will read zero–the black line lead and the white neutral lead complete a circuit, and current travels in opposite directions on those two wires.  To measure what you’re really after, you want just one of those leads in the clamp.

A line splitter makes getting just one lead in the clamp a plug-in operation. It also has one loop that is multiplied 10 times–which can be useful when you’re trying to measure smaller currents.  Another $15 gets you one of these to keep with your meter.