Extending thermocouple wires?
 

I got myself this handy new Mastech MS8229 multimeter, and it comes with a nice remote temperature probe. I believe its a K-type thermocouple. However, the leads for it really aren't that long. I would like to be able to measure the temperature of my oil pan (more info in this thread), and run the wires into the cabin. This means I need to extend the thermocouple wires. Doing a quick google search, this doesn't seem to be a straightforward ordeal. Can anyone explain this and how I might do it without buying 'extension wires' somewhere? Is it just a matter of shielding the wires from RF interference, and using a suitable gauge wire?

Before I knew how thermocouples worked I extended the harness on mine with 20ga wire.
Seems to work fine.

Is that the white braided looking wire with the banana plugs on the end?

I'd just get some female banana plugs and/or some extension leads, and try it...compare it to something like a laser temp reader. If you get weird readings, try twisting the wires around each other.

If I didn't give a damn about the wires, I'd just cut the red and black wires, solder in an extension and call it done. Can always twist them together later if they read odd.

The only way to do it wrong is to have different metals for the two conductors in the extension bit.

You'll lose accuracy with anything other than proper type K extension wire. If the extension portion is all at the same temperature the error will be small or none. If the extension section traverses a temperature change your error will be greater. If you're just looking for relative temperature, i.e. you want to see if things are 10 degrees hotter at one time than another, the extension wire won't matter.

(I used to measure temperatures for a living)