how would you go about measuring the voltage on a VanDerGaff generator ?
Let's say the voltage is 50KV, so then dividing it by x20K using a pot divider would give you 2v5 which can go into an ADC. However, if this was set up then it would probably cause the high voltage to arc down to ground.
I was thinking of something like a gold leaf electroscope (?) something I vaguely remember from school. Basically a thin sheet of gold that is repelled from a ground plane, the angle it lifts is a dependant on the voltage. Of course there's then the problem of measuring this deflection (I'm thinking of an LED and photodiode reflecting off the gold leaf).
Any ideas greatly appreciated