Re: Welding thermocouples??

[Andy Dingley]

I need to make some thermocouples (approx 10) for temp measurements in and

> around the house,

Just buy the things - they're cheap enough.

If you _must_ buy them, then build a capacitor discharge spot-welder for doing it, and run it in an inert shield gas (welder argon, or kids' balloon helium). If you're going to do a lot of this sort of thing, go the whole hog and recycle an old switch-mode PSU into a micro-TIG setup. Plans for both of these are around on the web.

For ambient domestic temperatures though, a solid state absolute temp. sensor is going to be a lot less trouble than a differential sensor like a thermocouple and having to do cold junction compensation.

[Harry Bloomfield]

Donwill wrote on 23/03/2008 :

There are single (and cheap) IC (chip) solutions which are both accurate and much easier to use than thermocouples. Look up the LM35 range...

[dutchman]

I have made type T engine bearing tc's in the past just by twisting the ends together and then encapsualting them in araldite.

Let them set and then test them to make sure there is metal to metal contact.

Perfectly OK for low temps.

And then slide them into a 3mm st st tube and araldited them.Then test them again and see if any touching the tube.

If using type K then use a capacitor discharge spot welder. Put the 2 wires on top of each otherand then onto a block of steel. Something that takes the heat away quickly, but allows just the wire to spot weld together.

I doubt if you will use type K as its more for very high temps.

[RustyRatchet]

(Chromel/Alumel)

stuff about hardware and software by interfacing some very cheap I2C temperature sensors to the serial port of my PC - see

.

[newshound]

I have soft-soldered twisted chromel-alumel (for low temperature use of course). Not sure if both wires wet properly but it worked.