Hopefully none.
I use a short extension lead that I made up with the cores exposed, and cable tied into bundles of ten turns. That way you can clamp round the x10 group when measuring lower currents to extract more accuracy from the meter.
not IME... also not as easy given the (relatively) high current draw, the actual power output varies quite a bit from the plate value with changing supply voltage.
I'd say neither would matter much compared to the difficulty in measuring the gas consumption accurately.
This was using a plug-through meter. It reads only integers on most ranges (not relevant at ~3kW but interesting for standby on the new telly) and seems to show the expected wattage on incandescent lamps.
Some sort of tea towel is needed.
I looked at a couple of gas bills after I posted that --- the variation is indeed pretty small.
Needs scouring first in a hard water area.
After boiling just one pan of water? I doubt it.
As I was drifting off to sleep a few days ago I came to the conclusion that it costs 0.5p to boil a mug of water with an electric kettle.
1/2 pint of water, 2kW kettle, boils in 60 seconds. So, 2kW * 1/60th hour = 1/30th kWhr 'leccy at 15p per unit -> 15p * 1/30 = 0.5pJGH
Coiling up extension leads is a no-no!
;-)
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.