Quote Originally Posted by object View Post
I like your execution, very cool. The reason probe ends, terminals, and test point connections are nickel, gold, or rhodium plated is that they don't oxidize. Because aluminum does it will directly affect readings accuracy. <<<<<<<snipped>>>>> Aluminum forms and oxide layer immediately after it's machined. It's basically an insulator. You can mitigate this (somewhat) by chasing the tapped holes again, quickly adding battery terminal dielectric gel then immediately reinstall the screws. for the banana ends you can fill the voids with the gel. The gel will prevent more air from reaching the machined surfaces. However, some air will reach them as oxidation is immediate after machining.

More here:

https://physics.stackexchange.com/qu...ce-oxide-layer
Recall from decades back, no one has ever seen clean aluminum. Even the marine grades, resistant as they are. The lowest grades, suited for extrusion "look" clean the longest, hence use as trim material indoors and out.