ThreePhaseElectricityMeter dial

Hiya
Bit of an odd question, would anyone know the accurate length measurement of the black section on the rotating Dial of the Three phase meter.

My mums was turning on its own when all power on the board was shut off, The electricity company have agreed it was creeping round and replaced it but have misplaced "that" old meter so cant provide me with this information......(the fact there's 100s still in existence you would think they could if they wanted too) The black area looks about an inch long but I need to know its length and also the full circumference of the dial so eg: how many times the black area would fit back into it.

I would be very grateful if anyone has a blue print detail or collects them and has this dial they could measure for me.

Thank you in Advance

Do you mean this black mark on the rotating disc?

because if you do, then the answer is that there is no specific length.

Some (like the one in the picture) are just a bit of black paint.
Others might have a defined length if the disc is printed with lines/numbers or other marks but even there, it all depends on the make and model of meter.

The size of disc varies with different meters. The number of disc revolutions per kWh also varies considerably.

If you wanted this to somehow work out the amount of electricity you were overcharged, then forget it - no way it can be done.

Hiya Flameport
Thankyou for providing the photo.
The overpayment was refunded once on these calculations
its just they never repaired it properly.
Since posting ive found the paperwork from the past issue in the loft.
The one that was taken out was a marked and measured printed dial with accurate markings they are the same for all meters on that power supply.
Thankyou again for Replying