'K' type thermocouple wire connecting to meter - a question

I have a meter with K type thermocouple. The wire welded blob at the measuring tip is discoloured from the manufacture but apart from that there is no visible insulation at all to keep the two different alloy wires apart in the fiberglass insulated sleeve (about 1.5 Meters long) that then goes to the yellow plug that fits the meter. I dont understand how the voltage generated in the tip by the two dissilar alloys can be measured at the meter when the two alloy wires are touching probably multiple times anywhere along the length of the connecting wire. Can anyone explain this? It definitely works but I dont understand it, the two individual wires definitely have no thin insulation but I suppose separation could be hidden in the tight weave of the fiberglass covering somehow but I cant see it! If you pull the fiberglass sleeve back there is no visible separator of the wires. Anyone have an answer to this? C+

Reply to
Charlie+
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The thermocouple is the fused tip. The wires going from there to the meter need to be insulated.

Reply to
Tom Biasi

They have to be insulated so there's probably some enamel on one or both. I've got some with (obvious - blue colored) enamel.

Reply to
default

Yes, the clear enamel is impossible to see and that's probably what they've used.

Reply to
Cursitor Doom

On Fri, 14 Apr 2017 14:16:13 -0400, default wrote as underneath :

Thanks folks for replies, these K thermocouples are OK up to 1300C so enamel would probably not be best choice. I have taken an even closer look, very difficult to see but they have wrappped one conductor in glass weave and then wrapped the second conductor to that first one with a second weave. Problem solved! The conductors are not insulated in anything that might be flammable or oxidize, meter tip runs up both bare conductors without any surface resistance. C+

Reply to
Charlie+

The gas hot water heater cut off about a year ago when there was no real reason to heat water as the cold water was already 30 C.

Nevertheless I pulled out the sensor, bent it away from the flame or scraped some crud off or something, and it worked!

Some rocket scientist at NASA claimed they had developed a material that "wouldn't accept heat" at a high enough temperature.

I'm thinking, that would really sell in The Valley.

Bret Cahill

Reply to
Bret Cahill

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