We have a Dent and it does OK. We actually use it to measure the power usage of various machines we make. I've also used an oscilloscope with a collection of Fluke HV probes and clamp on current probes.
Don't trust the batteries - plug it in.
One thing to note, don't believe the current probes for low currents. They are not 0-XX amps. When you get below 5-10A, they read poorly. The magnetic field from the current is weak at low current, so you'll get noise, and sometimes the device will force a no reading for low current.
A trick is to make a wire loop of 10 wraps, connect it in series with the power wire, and then clamp on to this loop. The current clamp will now read 10x the current. Thus is you have an 8A load, you'll read 80A, and if it has some idle mode where it draws 1-2, it'll still read 10-20 and you get better resolution.
And be careful to count the number of loops within the jaws. It's easy to get 9 or 11.
The vendor will try and sell you a set of "low current clamps" but a wire loop is cheaper, even with the price of copper going up.
Matt
