Other things you might overlook Thermocouple
Thermocouple can be one of those sweet surprises you find in a lot of scrap. Or it might be piled somewhere in the corner of a garage, forgotten, unknown. Most people do not know what thermocouple is. I have seen it at garage sales, flea markets, sold as plain wire or unknown metal.
Even thermocouple that is NOT made of precious metals is worth more intact, than scrapped. Specially rolls of thermocouple extension wire.
To identify the type of thermocouple you are dealing with, look along the wire shielding, you will see somewhere a single letter most likely proceeded by "TYPE" or something else that identifies the following letter as the type of thermocouple. For example if you look at the table below you will notice that type R thermocouple has 13% Pt and the rest Rh. Type R thermocouple will be identified by the color of the shielding, but also by stamped letters on the shielding itself that might include the manufacturer part number, but somewhere it will say "type R", you should know when you see that what type it is by referring to the table below.
Another way to identify possible sources of thermocouple wire is to look for applications where high heat is in direct contact with wire. Such as temperature probes for high temperature applications. They are almost surely made of some type of thermocouple. Thermocouple actually conducts electricity better when hot, unlike other types of electrical wiring.
Here is a table of the types of thermocouple and their color coding:
https://dl.dropbox.com/u/56505223/Th...or%20table.jpg
There is a ton of information about thermocouple all over the internet. It's uses, applications and different forms.
Here are some examples of what thermocouple might look like:
https://dl.dropbox.com/u/56505223/wrnk-171.jpg
https://dl.dropbox.com/u/56505223/20...ermocouple.jpg
https://dl.dropbox.com/u/56505223/Th...3HWL4_AS01.JPG
Here is a table of the types of insulation used in the production of thermocouple wire. I know some people, when scrapping, try to recover all the material that might be worth value.
https://dl.dropbox.com/u/56505223/th...insulation.jpg
I hope there are people on this forum that know more about thermocouple and can add more information.
Happy Scrapping
Scott
