2/11    Anyone have any experience with Clamp Meters to measure Amperage?
        Can they measure current through insulated wires, (e.g. on an
        extension cord) or do they have to be used at some particular
        location, or .. ?
        \_ There are 2 basic styles.  One plugs in in series with your stuff.
           This requires you to unplug your thing to put the meter in series.
           The other type goes around the wire and detects the magnetic field
           generated by the current.  This will not work on an extension cord
           because it's going around 2-3 wires and since it's catching the
           hot wire and the neutral (including the return current) the net
           flow through the device will be zero.  If you can split your
           extension cord or find an exposed wire in your wall, then you can
           use this type of meter.