Thermocouple wire type?

[tomhumf]

I need to get some new thermocouple wires like in the picture. They have flat 'ears' to connect to the thermocouples I use. All the ones on Amazon seem to have only one wire without the ears at the thermocouple end. Can anyone help me with terminology to track these down? Thanks 

 

https://www.amazon.com/Uxcell-K-Type-temperatura-termopar-alambre/dp/B00UBWR5T6/ref=mp_s_a_1_9?dchild=1&keywords=thermocouple+wire&qid=1595169587&sr=8-9

[Bill Kielb]

3 hours ago, tomhumf said:

Can anyone help me with terminology to track these down? Thanks 

Those crimp style wire connectors come in ring and spade. Big box home prosumer sell them. Most thermocouple holders are made for simple wire insertion and tightening. Using a ring or spade terminal crimped to tcouple wire will be less accurate than just embedding the wire under the screw and tightening. Your bottom connection in the picture appears normal, your top one with the spade crimp seems modified by someone - not necessarily better than the bottom connection actually. If there are no holes in the holder I am looking at then wrapping the wire under the screw with a  bottom washer and top washer, wire trapped between is probably best followed by any crimp whether ring or spade. No need for insulated crimps here actually, they will only melt and discolor in the heat. Picture of Typical wire below the pvc is popular.

Just reading this, the connector on the end is a meter or mini thermocouple connector  that often  is polarized. One tab is wider than the other. Anyway, you can take this apart and install new tcouple wire to it just remember the polarity. These can be purchase separately as well, just be sure to specify the K type.

[neilestrick]

Like Bill said, you can get the terminal ends you need at any hardware store. Just strip back the wire and crimp them on. However I believe that your thermocouple block (at the kiln) has holes for the wires to go into, so you shouldn't need them. Just strip back the ends of the wires, double them over, insert them in the holes, and tighten the screws. If that's the same block I bought a few of recently, you'll need to remove the washers from the screws in order for them to tighten enough.

I use THIS wire. It's a little larger so the connections are less likely to break, and shielded.

I'd also change out the screws on the porcelain block since they're so corroded. If the brass blocks that the screws go into are also corroded, replace the whole porcelain block. You want clean connections.

[tomhumf]

Right, the spade fell off one of the connectors because I move it between kiln a fair bit. I did just hook the bare wire round and screw in, I thought maybe this was a bit of a bodge though.

I will get some new wire because it's pretty beat up, but I'll just connect it direct if that's good then. I have some newer thermocouples I'll start using without corroded bits. 

What happens if polarity is wrong, it just gives no reading? 

[neilestrick]

52 minutes ago, tomhumf said:

What happens if polarity is wrong, it just gives no reading? 

If polarity is wrong, it will read about the same at 70-75 room temp, and you won't know it's wrong. But as the kiln temp starts to climb, the TC readout will go down. This will result in an error code on your controller when it gets far enough out of whack.