Arduino Current Sensor

I wish to measure the current at the secondary of a weld transformer (salvaged from a microwave oven). Are there any sensors that can measure high current. The measurement would be for a very little time, as little as 500ms. Found one on ebay. How good is that ? is that a very low spec ?

Try this - just measure the voltage.
Then Power = Voltage x Current.
700W microwave oven, say 500V out, then 700W/500V = 1.4A maximum.
The Microwave tube is going to be pretty high voltage. If you have 120V going into it, be quite careful measuring the output.

well i am not sure what the wattage of the transformer is either. Just measured the voltage at the secondary to be 2.4VAC. That would be the MAX current, What about for milliseconds?

Does anyone have any experience with this 200A current sensing Module. It says it is compatible with the Arduino.

How much current would be flowing for 500ms from a MOT ? Would this blow if connected to a rewound Microwave Oven ?

A few concerns before i order it. I have a Rigol 1054z Osci. Guess it cannot be used to measure the current.

Thanks in advance.