Dear Kai,

Thanks for your kind reply,

Maybe you overrange the integrator, by using a too small integration resistance? Try R = 100kOhm instead, or choose a Rogowski coil providing a smaller signal, means containing less windings.

I changed the resistor R to 47k and the Ra to 10K and with this setup I could see a change in integrator output.

Or is it, because Rogowski coil isn't shielded and capacitive coupling of switching noise takes place?

Although at present I am not using any shield for my rogowski coils but I will certianly use shielded coil for production purposes. Can I use aluminium foil for shielding purpose or something else? Apart from this electical shield I will also be using Asbestos shield for protecting coil from welding spark and heat.

Thanks for explaining the offset elimination using the trim pot. I have already ordered TL052 through RS I will be using only TL052 and not TL082 for production purposes.

Regards,
Prahlad Purohit