Chabiraj,

Depending on the neon voltage it will operate properly up to about 50-90 kV. I wouldn't trust the insulation above 30 kV myself.

Built better I'd use it to 50 kV. If the neon starts the glow it will be clamping the voltage and it will no longer be linear.

Regards,

Alan

Please tell me how much kvs d.c volts your probe can test. thank you C. Persaud.