G \$\Omega\$ Input impedance Voltage measuring up to 1kV

[Jester]

I was working on a circuit the other day that measures ac/dc voltage up to 1kV. The input impedance of the circuit is ~2M , so simply connecting any of my DMM's (10M input impedance) loads the circuit considerably. I do have several 34401A's however the high impedance mode can only be enabled for low voltage ranges.

So perhaps I should build a high voltage, high input impedance circuit for the next time I need to make a similar measurement.

Can anyone point me to an appropriate app note?

[EEVblog]

https://www.eevblog.com/forum/projects/hi-z-high-voltage-probe/

A contact electrostatic voltmeter might do the business, maybe something like this
http://www.trekinc.com/products/esd_voltmeters.asp

[joeqsmith]

My $50 multimeter goes off in the weeds whenever I start making even tiny sparks.

[Jester]

I'm envisioning a circuit something like this:

R1,R2 are 1%, rated for 3kV working voltage
R5, R6 are to match the gain, I would hand pick them

Output drives 34401A, the 10G input resistance mode only works on 10V and lower ranges, so this circuit would be used for V > 10V

OP07, is not great with lower input voltages, perhaps an alternate with lower input current OPA191?, suggestions?

Please critique and suggest ways to improve.