Memory aid for memorizing Thermocouple types materials and colour code

GopherT

Joined Nov 23, 2012
8,009
Help please.

I need to memorize thermocouple types j k e and t with type colour and material, anyone have some memory devices, or ?????
Use them, design a project around each of them.

Then make flash cards and quiz yourself and have a friend quiz you. If that is the test your teacher is giving you, some times you have to buck up and rute force it. There is no easy answer - there is just hard work. Get to it.
 
Easy part. RED is negative - always.

K has a yellow jacket

J and K are really close though, so be careful.

You really don't. If you use them enough, it becomes natural.

One other "gotcha" is that some readouts/controllers might not be valid at room temperature. I had some that would start at 250 C.

A shorted input to a meter/controller should yield the minimum temp or the lowest temp of the display.

It's useful to use your finger on the end of the TC to make sure the temperature rises.

The rules seem to be use K when you can. T when your dealing with cyogenics and temperatures around room temperature. R&S are pretty fragile because of the platinum. Cyogenics is best done with a diode sensor. "C" when stuff gets really hot - i.e. above the melting point of copper.

Some companies make stupid cold junction compensation. Initials are MC.

Watch out for extension vs. TC cable.

Fine thermocouple attachment to plugs requires a Teflon washer.

Use isolated junctions when you can.

Junctions can be made, but make sure there is only one twist. A torch can do R and S. A carbon block can do J and K. So can spot welding.

Multiple junctions average the temperature.

Remember the word ISOTHERMAL. Each connection can be thought of a 1/2 junction especially if the temperature is not equal.

Medium compatability is another area. We used some Tantalum sheathed thermocouples.

Use the right feed through, There's a company that can make a vacuum feedthrough with any mix/match TC you want.

The color is small potatoes. You have to wrap the fact that RED is negative. Just like in the US, standard house wiring is: Black (hot), White(neutral) and bare, green or yellow w//green is ground. Battery cables. if your lucky RED is positive.

RTD's when the temperature is <= about 250 C.
 
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