Chinese Kelvin clips, Banana plugs and Posts.

[Gyro]

Copper - Tin/Lead solder 1 - 3uV/'C Can't find a figure for unleaded.

[henas]

For gold/copper EMF is 0.5uV. I believe this is for 24 carat gold.
In case the plating is not pure gold and there is nickel barrier used underneath I would expect EMF will exceeds 0.5uV by substantial amount. This leads me back to the same conclusion the difference is not that great when the solder is carefully chosen. 

Any thoughts???