Multimeter

SimpleThings:

BillHo:
Digital multimeter shield for Arduino

http://duino4projects.com/digital-multimeter-shield-arduino/

This is already made multimeter if I am correct, but I want to make my own.

No, the link from BillHo is to a project to make a DMM shield from parts, not an already made multimeter.

And it looks like it may be a good one.