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.