>>> I would like to get any feedback or experience info on whether Deoxit would help sufficiently to improve mechanical switch contact performance used in very low (nV) level circuits. Both the Agilent 34420A & Keithley 2182A nV meters use Lemo connectors and their docs suggest DeoxIT (this is when talking about connectors). e.g. from the Keithley doc: "Make sure that all connections are clean and free of oxidation to avoid thermal EMFs that could affect measurement accuracy. Clean oxidation from connector terminals with DeoxIT cleaning solution." Link: http://www.anagram.net/nuts/2182A/Docs/2182_nanovoltmeter_service.pdf >>> , I'm feeling better about going with my mechanical switches with Au and Ag contacts and Deoxit combo. If worse comes to worse, I guess I could scrape off the plating and go Cu all the way, but I don't think that will be needed. FYI the contacts of the Lemo connectors look like naked copper to me.