29 Jun
2004
29 Jun
'04
2:17 a.m.
>>>> "Philip" == Philip Pemberton
<philpem(a)dsl.pipex.com> writes:
Philip> In message <16609.29143.964000.962537(a)gargle.gargle.HOWL>
Philip> Paul Koning <pkoning(a)equallogic.com> wrote:
> Interestingly enough, nichrome is also used in
thermocouples.
Philip> Really? I thought the stuff used in thermocouples was a
Philip> copper-nickel alloy?
I think we're both right -- there are three or four alloy combinations
in common use, and several more that are not so common.
Here's a reference...
http://www.omega.com/toc_asp/frameset.html?book=Temperature&file=tc_col…
-- which mentions nichrome as the + wire of a K thermocouple (yellow
plug), and copper/nickel ("constantan") as the - wire of a J
thermocouple (black plug).
For really esoteric, consider the R type: platinum/rhodium alloy for
one wire, pure platinum for the other.
paul