Stan, I recently picked up some of these ... http://www.douglasconnection.com/Furez-TSTWP30NP-Bare-Copper-Banana-Plug-Connectors-Pair-FZTSTWP30NP.htm
They are a little pricey and are made for 12ga wire. I think they are OK for semi-permanent use. A lot of use will probably scratch the soft metal. I plan on trying them with my Keithley 181 plugged into a low thermal scanner. The original Keithley cable will be difficult to terminate. I may have to go with crimped spade lugs. Also, I am all for joining a beer nuts group. Todd On Tue, Aug 19, 2014 at 2:07 AM, Stan Katz <[email protected]> wrote: > I'm a self described volt-nut-near-beer. I don't own a 732A/B, or an > HP3458. I do own HP3456 DMMs that are at the top of my instrumentation > pecking order. I have all the necessary gear to calibrate these DMMs > according to ancient HP documentation. At the top of my cal. chain is the > 731B, called out in HP3456 original documentation. This hierarchy places > me in the near-beer, or junior member status of the group. I look forward > to being educated, and/or corrected on my understanding of the use of test > leads with precision instrumentation. > > I don't find much ancient HP documentation on test leads. The only > recommendations in the era of the 3456 back to the 1960's is to use as > thick a solid lead of pure copper wire as you can find, and insert the wire > into the drill hole on the banana terminal. If the copper is pure, and has > been properly cleaned, the thermal emf's on both identical length leads > should all be balanced, and cancel out. In any case, pure copper-copper > connections generate the lowest thermal emf. I will agree that manhandling > 16 gauge solid wire can be very inconvenient. > > The path I have taken recently is to order Nakamichi gold over copper > stereo banana plugs for my connections ( I deal in low voltage work > exclusively), as well as gold plated spade lugs to go under the banana > screw-downs. ( My budget ruled out gold over beryllium copper Pomona brand > spades. ) I will then experiment between the two connector types. As for > connections, it seems to me the best course is just to screw down the > banana plugs, or in the case of the spades, just crimp. I'll wing it on the > crimping, and see if simple tools can perform adequately. I would avoid > solder, since how can one form identical topological spots of solder on > every connection, deposited at the exact same place on each connection, and > ensure the exact same weight of solder, to the microgram, on each > connection. Since my modus operandi is to aim for balanced emfs, I think > solder is out. Of course, if one wishes to risk one's health, and that of > the family, one can track down a source of cadmium, and mix up a lot of low > thermal emf solder (cadmium solder is banned in the US, and EU)...not for > me. > > Don't worry, I won't be using tin plated wire, I managed to pick up a spool > of silver plated 16 gauge wire for my investigations. Am I on some other > planet for choosing the balanced thermal emf approach for precision test > lead applications, as opposed to going to great lengths to eliminate every > trace of emf? > > Please forgive me if these emf discussions have been between engineers > working outdoors in the oil fields of North Dakota, or out on a North Sea > drilling platform. In that case, go for all the super low emf techniques > you can lay your hands on. > > Good Luck, > Stan > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
