David82:
PeterH:
....the whole circuit is under your control, then you could try either using DC (I have no idea whether meters would detect that) of a very high frequency AC well outside the range the meter is designed to pick up.what do you mean by this?
Well, if the meter is designed and optimised to detect AC current then it may not detect DC current - or may not detect it well. If you have complete control over the circuit and can arrange for your supply to be DC rather than AC (or to have a significant DC component in addition to the AC) and IF the meter does not measure DC current then you'd be able to get power through the meter without it registering.
Alternatively, if the meter has been designed to selectively pick up mains frequency signals then it may not be able to pick if signals at a much higher frequency. For example, it's possible that if you send an RF signal down the line, the meter would ignore it (it would be filtered out). I'm speculating, because I have no idea what range of frequencies the meter deals with, but if you have full control over the circuit then it would be worth a try.
I don't feel optimistic that any of these approaches will work, but if you have a meter and time to play with it, what do you have to lose? Probably the most promising way to obtain power without it registering at the meter is to cheat. But that's hardly going to get you any credit when it's found out.