How we can monitor uA current in data acquisition system?? i mean method.

 

Pass the current through a resistor and amplify the voltage across the resistor?

Use the current to charge a capacitor and measure the voltage across the capacitor after time t?

 

Buy a data acquisition board off ( eBay ). Software is free from national instruments. Then use differential analog inputs on the board to monitor current as a voltage drop across a resistor.

http://www.ni.com/products/usb-6008/