MCM Electrronics: type K beaded thermocouple w/mini connector, $7.56

[ecc]

It took a while to deteriorate.  More likely a combination of abrasion, some fiber melting together, and extrapolation on my part.  It must have looked pretty bad for me to throw it away, though...

Here is the Omega data sheet for tc insulation, couldn't seem to find it before.
http://www.omega.com/techref/wireinsulation.html

That's what I was looking for - thanks!! The insulation Omega puts on t/c's is TT (PF) & GG (hi-temp glass). Since my roasts never intentionally  get over 500°F there's never been a problem.

Obviously my roaster is not the same as your roaster, but I routinely measure ET temps over 260 C (500 F) that can get up to 300 C (572 F) in parts of the roaster during limited airflow drying.  Safety first, cheap second! Then, the frou-frou.

[randytsuch]

Attached is a pic of my cheap chinese fiberglass type k tc, installed to measure et in my alpenrost.

I don't know if is black from chaff ash, or something else, but I would guess it's ash.

I got it back in Nov, maybe do a few roasts per week on it.
It works fine, as far as I can tell.

Where it sits, temps always go over 500f for a roast, I did a few where temps went over 600.

Randy

[Roasting Realtor]

I would use a type K stainless steel clad, grounded, 3mm or 6mm TJ36 type probe from Omega inside a roaster.  

You can gently bend this probe to get it stay where you want, the stainless steel won't degrade into anything nasty and makes it easy to clean.

A little more expensive at $45, but is stable, accurate, and will last a long time.

where do you get the SS probes?

[ecc]

I would use a type K stainless steel clad, grounded, 3mm or 6mm TJ36 type probe from Omega inside a roaster.  

You can gently bend this probe to get it stay where you want, the stainless steel won't degrade into anything nasty and makes it easy to clean.

A little more expensive at $45, but is stable, accurate, and will last a long time.

where do you get the SS probes?

http://www.omega.com/ppt/pptsc.asp?ref=TJ36-ICIN&Nav=tema07