Tkosiyat: Check out these manuals.
Tkosiyat: The multimeter used in this application note in not a normal DVM. This is an expensive Multimeter that can remove current injection from the multimeter.
Input bias current:Ideally, no current flows into the measurement terminals
of your DMM. In real measurement situations, there are always input currents
creating additional measurement errors. Truevolt DMMs take care of input bias
current. Some alternative DMMs offer 20% to infinitely poorer performance
(some are too noisy to measure). I think you are measuring noise and other current loops not the device.
I think I need a a good multimeter. Can you recommend me one?