High Current measurement Answered

I need to measure Current from a welding machine to make a alarm if it goes down below some level for ensuring better quality of welding.

The current normally set is of the order of 200A max with around 100V DC.Not sure if i could use some clamp-on meters and pass those values out to Arduino for switching circuit.

Shunt resistors may be a better option. But to make a signal conditioner to convert the ma output will be a problem i guess..is there something i can do with Arduino..

any ideas guys....?

Thanks in advance

Chuppandi