In article , Bob
Minchin writes

MrCheerful wrote in message ...

"tony sayer" wrote in message
...
In article , MrCheerful
writes

"John Horne" wrote in message
...
A friend of mine asked the local electricity company to install a
"white
meter",
Economy 7 type thing to power his night storage heaters.

The company said that it is not their policy to install such meters
anymore,
and that it is all done by computer.......!! This answer intrigued
me,
any
idea what the chap was talking about?

They remotely monitor the new meters,

How?...


I believe there is some sort of pulse put out over the mains feed which
identifies your usage.

MrCheerful


A phase modulated signal is sent out on Radio 4 longwave, 198kHz which is
detected by the leccy meter and switches the consumption recorded between
standard and off peak.

Phase mod is used so that the signal can also be used a stable frequency
reference for other purposes.

Bob



That's controlling your meter, not "monitoring" it.....
--
Tony Sayer