thermocouple wire terminals

[1bigdog]

I don't see anywhere in the Garmin docs, or Alcor sheet that came with the engine kit about attaching the probe wire to the thermocouple extension wire.
Since the probes come with a ring terminal I'm guessing the best way to terminate is like terminations screwed together.

I don't see anything like Alumel/chromel ring terminals readily available.
As a sanity check just want to confirm that using a quality Amp ring terminal on both extension wires cancels out the error introduced and no one has seen issues with this type of installation. I see Aeroelectric did an alternate method using crimp Pin/Socket.

Thanks for the insight from the masses.

[1bigdog]

Originally Posted by 1bigdog

I don't see anywhere in the Garmin docs, or Alcor sheet that came with the engine kit about attaching the probe wire to the thermocouple extension wire.
Since the probes come with a ring terminal I'm guessing the best way to terminate is like terminations screwed together.

I don't see anything like Alumel/chromel ring terminals readily available.
As a sanity check just want to confirm that using a quality Amp ring terminal on both extension wires cancels out the error introduced and no one has seen issues with this type of installation. I see Aeroelectric did an alternate method using crimp Pin/Socket.

Thanks for the insight from the masses.

And my mistake. A simple search found that Omega sells the type k pins/sockets.

[sblack]

I use silver solder with flux, like staybrite, and a butane pencil torch, then cover with heat shrink. Normal tin lead solder won’t work. I bought a spool of thermocouple wire rather than paying through the nose for those extensions. Then I made all my tc leads to the exact length required. I guess you already bought the extensions. Silver solder works very well and is more reliable than a mechanical connection.

[1bigdog]

Originally Posted by sblack

I use silver solder with flux, like staybrite, and a butane pencil torch, then cover with heat shrink. Normal tin lead solder won’t work. I bought a spool of thermocouple wire rather than paying through the nose for those extensions. Then I made all my tc leads to the exact length required. I guess you already bought the extensions. Silver solder works very well and is more reliable than a mechanical connection.

I didn't buy the wire yet. Just got a call from Omega they have stock of #24 but 22 is 9 weeks out. So I'm debating about the size as well.

I did consider just silver soldering, and I agree that the connection is mechanically solid. I like the serviceability of the terminal solution but I guess solder would be the fallback position.

Thanks.

[wjb]

The Alcor EGT and CHT sensors (Garmin G3x kit) come with standard #4 tin plated copper terminals crimped on ... I crimped on the same terminals onto the extension wires, screwed them together with the provided #4 hardware. In principle, one would use connectors made from the proper alumel/chromel connectors, but if the connection doesn't have a temperature gradient across the connections, it won't give rise to a indication error. Copper is a fantastic thermal conductor and they are pretty well insulated thermally, so I judged that any dissimilar metals connection error will be negligible.

[Rainier Lamers]

Quite OK to connect thermocouple wires using copper, brass or even zinc plated copper/brass spare terminals or crimp connectors.
You create TWO new thermocouples. But they create an opposing voltage that is the same if the temperature is the same (which it pretty much will be). So, they simply cancel out and the net effect is zero.
One of the times when the ball bounces your way...

Rainier
CEO MGL Avionics

[1bigdog]

Looks straight forward then with several low hanging fruit to move forward.
Greatly appreciate everyone chiming in to settle this.

[9GT]

I never gave it a lot of thought when I hooked up the wires on my RV-10 and just used standard size Garmin D-Sub pins and sockets , then covered with shrink tube. It worked great so I did the same on the -9A.

[supik]

Is this the proper Omega ring terminal?

RLNC-22

https://www.omega.com/en-us/control-...tool/p/RLNC-22

[RV6_flyer]

Originally Posted by Rainier Lamers

Quite OK to connect thermocouple wires using copper, brass or even zinc plated copper/brass spare terminals or crimp connectors.
You create TWO new thermocouples. But they create an opposing voltage that is the same if the temperature is the same (which it pretty much will be). So, they simply cancel out and the net effect is zero.
One of the times when the ball bounces your way...

Rainier
CEO MGL Avionics

That is what I did 23-years ago and it has worked well.