# Platiunum and other PGMs from Thermocouple wire



## lazersteve (Apr 5, 2007)

Does anyone know the exact types of thermocouples that have the PGM alloys in the wire? What portion of the wire has the alloys? Please specify the applications and where they can be salvaged from. What devices use the thermocouples with the alloyed wire? I've tried to find info and can't seem to get more than just that they exisit. I'm interested in harvesting this type of scrap.

I have found this information on the various types of wires:

http://www.oegussa.at/neu/englisch_...rospekt_THERMODRAHT_englisch_aktuell_0506.pdf

I would like application information.

Steve


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## AgAuPtRh (Apr 5, 2007)

http://www.omega.com/prodinfo/thermocouples.html

Thermocouples come in "types"

The type K thermocouple has platinum and I believe the type R have platinum.

You might also want to look in to old aircraft parts. Some of the Pitot tubes have platinum.


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## jimdoc (Apr 5, 2007)

K is chromium nickel and a very common one.
I think the good ones are R and S and possibly B.
Look on the web for a color chart, they will be pairs
of certain colors. If I find the link again I will post
it. I cannot help you in where to find them except 
in high temperature applications, and furnaces.


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## jimdoc (Apr 5, 2007)

Here is a link for the colors, and temp. applications
http://www.omega.com/techref/thermcolorcodes.html


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## goldsilverpro (Apr 5, 2007)

Here's another link.
http://www.noble.matthey.com/products/detail/index.asp?article=42

According to this link, there is also a clad variety that I have never seen. It would be worth much less than the more common solid variety.

None of the scrap wire I have seen was color-coded. 

The most common varieties are type S (90Pt/10Rh) and Type R (87Pt/13Rh). The wires are used in pairs, with one wire being pure platinum and the other a platinum/rhodium alloy. They are used mainly for high temp applications and/or highly corrosive applications.

When you have a bunch of wires, it's hard to figure out how to sort them. They look the same. With rhodium being worth 5 times as much as platinum, it would bring more money if you could sort them. Probably, you could use a wire, known to be pure platinum, as a standard and then mate the unknown wires with the platinum, one at a time and, determine any voltage. You may have to heat the junction to get enough voltage to determine. I would think a Pt/Pt junction would give no voltage.

Much of the wire I've seen was hot - it was stolen from the workplace.

While in college, I had a job making thermocouples, in Dallas, for Honeywell. We made very few of the platinum type. There are few applications that require them. I can't imagine thermostats being an application.

Speaking of thermocouples, in the late '80's, I was waiting for a guy in his living room while he was doing something outside. On a shelf, there was a set of cheap, grocery store type encyclopedias. I remember the publishing date was 1965. I was interested in thermocouples, at the time, so I pulled down the T volume. In it, there was mention of a semiconductor thermocouple array patented by some guy and assigned to RCA. The device was 1" thick and 12" square. When you put the device into a 750 degree F furnace, it would generate enough electricity to supply an average size home. The guy was quoted to say, "Now, every man will be able to generate his own electricity." 

When I got home, I made all sorts of diagrams, and researched the Seebeck effect of semiconductor couples. I didn't have much luck. I'm pretty good at searching patents but, this one seems to have totally disappeared. I know that thermoelectric generators have been around for awhile. If fact, I think they use some on the moon to run equipment. I guess I'll always be a conspiracy buff at heart.


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## AgAuPtRh (Apr 5, 2007)

I was wrong -- Again -- Type K aren't Platinum.

Heres is a link with the thermocouples and the metals used. Fairly comprehensive listing. Excellent reference.

http://www.facstaff.bucknell.edu/mastascu/elessonshtml/Sensors/TempThermCpl.html


Steve K


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## austexjwlry (Jun 15, 2007)

We bought a new digital beadmakers kiln from www.lincoln glass for $700. wholesale almost $1400. retail locally. Anyway it arrived damaged
in shipping, broken thermocouple. Was replaced for free and stated to contain platinum. Still have if you would like picture.

Your general reaction list was awesome!

Wayne


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