"George (dicegeorge)" wrote in message
...
I've read here that clamp meters are about 5% accurate,
so if I bought one like this for £20 (+vat+postage)
http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/

0.1amp = 24 watts
so could I have one before the Consumer Unit
and use it to check if anyone's left lights on,
or got a electric fire on etc?


Not really.........
I have a B&Q remote monitor and you can certanily tell if anh apliance is
left on
that takes significant power but small things are difficult to detect and
account for.
as an example, I have a fridget, freezers that switch on/off a thermostat in
my aquarium
all in all I use between 0.5 to 1 KWH . It's difficult to tell if it goes up
from 0.5 to 0.7
is that my bedroom light switching on or my freezer motor, or perhaps the
fish tank heater.
(250W) I even noticed a change when I use dimmers on my lights but to be
able
to tell whether a small appliance has been left on is impossible.
My two Macs computers use about 100W and 130W, I can just notice when the
screen saver
kicks in provided nothing else in the house has changed at that instant.
Although I certainly notice when my kettle 3KW, electric cooker or
Ecom 7 storage radiators come on. ;-0
So yes you could possible use it to 'monitor' certain appliances provided
you know
what else is eating your amps.