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?


http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter


Data hold and peak hold functions

DC Voltage: 1V - 1000V (±0.5%)
AC Voltage: 1V - 750V (±0.6%)
AC Current: 0.1A - 1000A (±2.0%)
Resistance: 200 ohms - 20k ohms (±2%)
Insulation test 2000M ohms Max.
Max. display 1999
Jaw Size 58mm



--

[george]

In article ,
"George \(dicegeorge\)" writes:
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?


http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter

This is what the Eco meter (discussed in another thread) would
be perfect for, and better than your proposal. As long as you
don't want to take accurate readings from it, it will give a
clear indication of significant loads.

Heaters cycle on and off on thermostats, and you will only see
the heater load when it's cycled on though.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Nov 12, 6:00*pm, "George \(dicegeorge\)"
wrote:
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?

http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter

Data hold and peak hold functions

DC Voltage: 1V - 1000V (±0.5%)
AC Voltage: 1V - 750V (±0.6%)
AC Current: 0.1A - 1000A (±2.0%)
Resistance: 200 ohms - 20k ohms (±2%)
Insulation test 2000M ohms Max.
Max. display 1999
Jaw Size 58mm

--

* * * * * * * * * *[george]

It doesnt say 5% it said 0.5 thats a half a percent, about half a
volt. What are you realy trying to do, is a tenant going out leaving
stuff on, In the US we can buy something that goes on the meter with
remote reader, you could get a data logger to the computer. If you
want to find shorts get a Clamp On that goes to.01a. A Kill-a-Watt is
great for apliance monitoring, if its a tenant and you pay the
electric, thats a problem.

On Thu, 13 Nov 2008 00:00:31 -0000, "George \(dicegeorge\)"
wrote:

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?


Can't you just ask ?

You do have to be able to clamp around a single conductor, not around
the live/neutral pair, and not around screened conductors.

"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.

George (dicegeorge) expressed precisely :
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?


http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter


Data hold and peak hold functions

It actually says +/- 2% on the current range, which is more than
accurate enough to decide whether a light(s) have been left on. There
are though better ways - look on ebay for a gadget which provides a
wattage read out remotely. You clamp it around a cable, then a remote
wireless display displays the wattage being used constantly.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Nov 14, 3:15 am, " wrote:
You do have to be able to clamp around a single conductor, not around
the live/neutral pair, and not around screened conductors.

What kind of screened conductor would not work with a clamp meter?

On Thu, 13 Nov 2008 00:00:31 +0000, George \(dicegeorge\) wrote:

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?


http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter


Data hold and peak hold functions

DC Voltage: 1V - 1000V (±0.5%)
AC Voltage: 1V - 750V (±0.6%)
AC Current: 0.1A - 1000A (±2.0%)
Resistance: 200 ohms - 20k ohms (±2%) Insulation test 2000M ohms Max.
Max. display 1999
Jaw Size 58mm


It looks as if you have 2 AC current ranges. The high one will be 0-999A
and the low one (at a guess) 0-99.9A. Remember that the accuracy will be
something like 2% +/-1 digit at best. So your indication with an accurate
1A current could be anything from 0.8 to 1.2 on the display if I've
figured this out right! Assuming that you won't be exceeding 100A, then
you may just be able to detect a 100W lamp with some accuracy, but
nothing less than that.

Clip-on ammeters aren't usually all that accurate anyway. Keep the jaw
surfaces scrupulously clean and the conductor in the centre of the loop,
with other cables as far away as possible for best results.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

On Nov 14, 12:51 pm, mick wrote:

Clip-on ammeters aren't usually all that accurate anyway. Keep the jaw
surfaces scrupulously clean and the conductor in the centre of the loop,
with other cables as far away as possible for best results.

Have you tested a clamp meter with the conductor not in the centre of
the loop, or with other conductors nearby? I haven't, but I'd be
surprised if the position of the conductors had a noticeable effect.
Assuming of course that the jaw surfaces have closed properly.