Stopping/Slowing Power Meter with Magnet

Does anyone know if there is any power meter that cannot be slowed down
by a magnet? I have successfully stopped my power meter from spinning
with a powerful magnet but recently the power utility changed my meter
to a new one, which looks similar to the old meter but its casing is
frosted. When i tried the same magnet trick on this new meter, it
doesn't seem to do slow down the meter from running. In fact, as far
as i can notice, the magnet doesn't seem to be able to affect the meter
at all. Could they have shielded the meter magnetically? Does anyone
know where else i can place the magnet? By the way, for my old meter,
i placed the magnet at the bottom part of the meter casing and that
seem to stop the meter.