Any instrumentation experts with advice on thermocouple & meter ?

[Simon47]

I know there are people here with some fairly niche and/or unusual knowledge & skills, anyone have any comments for this ?

I have a meter with thermocouple and I'm not sure it's the right thermocouple for the meter. It's "fairly old" - my late father would have acquired it from work when it was being thrown out, and he retired nearly 30 years ago.
I'm assuming the wire was some that he scrounged along with the meter, and the tip is home-made. I'm assuming the tip is welded, then it's taped to a bit of paxolin for support.

I'm assuming that where it says "Cr/Al" that means a chrome(alloy)/aluminium couple, but I've been unable to reconcile that with the wire colours from any table I've found online.

I'm assuming, based on where it would have come from, that this wasn't some cheap rubbish meter. Were they considered good/bad/indifferent/something else ?

Any thoughts ?

 

[GBDamo]

I know there are people here with some fairly niche and/or unusual knowledge & skills, anyone have any comments for this ?

I have a meter with thermocouple and I'm not sure it's the right thermocouple for the meter. It's "fairly old" - my late father would have acquired it from work when it was being thrown out, and he retired nearly 30 years ago.
I'm assuming the wire was some that he scrounged along with the meter, and the tip is home-made. I'm assuming the tip is welded, then it's taped to a bit of paxolin for support.

I'm assuming that where it says "Cr/Al" that means a chrome(alloy)/aluminium couple, but I've been unable to reconcile that with the wire colours from any table I've found online.

I'm assuming, based on where it would have come from, that this wasn't some cheap rubbish meter. Were they considered good/bad/indifferent/something else ?

Any thoughts ?

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No expert but isn't Cr/Al a K Type thermocouple?

 

[Darkwood]

You should be fine with a Type K

Nickel/Chromium - Nickel.Aluminium (Nickel just stops corrosion and aid temp tolerance)

Colour code UK would be:-
Brown +
Blue -

Red sheath.

Max continuous temp is about 1100c

PS - if the existing is original colour code cable then that would indicate a Type T is been used copper / constantan (copper/nickel alloy)..
This will be wrong hence your meter will not read the correct temp with probe in use I suspect.

 

[Simon47]

Oh, now I think about it, I have one with another meter (a modern but "not expensive" clamp meter) ... tried that and it gives much more plausible readings ? Before, my body temp was apprantely under 30˚C ?
So decent Type K probe to go on my shopping list.

Thanks guys.

 

[Darkwood]

You can buy very cheap welded tip simple wire versions for next to nothing, they still give reliable results, the only real reason you want to fancy up a thermocouple is for it mounting application like when fitted to a oven or machine control.
It is likely the meter will need calibrating though given its age and the sticker on it so unless you can verify the reading with a known heat source then take the reading with a pinch of salt.