All this talk about thermal EMFs may not be particularly relevant. Solder is used in connections between two metallic objects, like wire and a terminal. The thermal EMFs between a soldered copper wire and copper terminal have exactly equal and opposite values between the solder and the metals. I first met this in mid 60s making thermocouples, I was told that they should be welded not soldered because of the solder metal EMFs. I did both soldered and welded over the years, mainly for practical considerations, and although some situations were quite critical, I have never found evidence that solder matters. Even if you consider a metal like tin diffusing into the copper and changing its EMF, adjacent to the area of diffusion is a reverse gradient of tin concentration and thermodynamic considerations dictate that there is no effect for static conditions. The worst effect is the response of the junction to a persistent thermal gradient, but this is hard to maintain over the distance of solder thickness. cheers, Neville Michie
> On 9 Jul 2016, at 8:56 am, Herbert Poetzl <herb...@13thfloor.at> wrote: > > On Wed, Jul 06, 2016 at 08:53:19PM +0200, Andrea Baldoni wrote: >> On Wed, Jul 06, 2016 at 03:42:18PM +0200, Herbert Poetzl wrote: > >>> Any plans on testing Sn42/Bi57.6/Ag0.4 ? > >> Hello Herbert. > > Hey Andrea, > >> I don't have any source of it. My supplier (Heraeus) hasn't it, >> at least, it wasn't included in the list of samples they are >> able to give me on request. > >> If you have it and you could ship it (a meter of 0.5-1mm wire >> or so would be sufficient for me and I will give it back >> after), I will be happy to test it. > > Send me your address (off list) and I'll send you a meter for > testing. > > Best, > Herbert > >> Today I received the Sn99.3/Cu0.7 and I will post result soon. > >> Best regards, >> Andrea Baldoni >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.