Opinion On Thermocouple Probe & Chimney

[cabako]

Hi again all,

 

Here is a pic of the type-k thermocouple probes.  These are very thin and long, I was planning on just poking them through the ceramic fiber wall of the kiln.  Would one expect these to last long as is?  Could I shield them in some manner such as wrapping them in scraps of fiber?  Should the entire length be extended into the kiln or just a few inches?

 

I also have a used furnace (held continuously at 1050 C), that could be hollowed out and used as a chimney if necessary...or maybe use it as a port for the propane burner...not sure what to do with it.

 

Thanks,

[Magnolia Mud Research]

There is an optimum  immersion depth into the hot zone.  You can try various positions and see how the TC responds, but allow at least 5 minutes for the reading to stabilize.  Keep good records for the  immersion depth and use the same one for future firings.  I would start at about 10 cm and work backwards.   If 10 cm is more than half the diameter of the furnace, start at the center.

 

A good reliable source of information on thermocouples is Omega.
you will need to poke around the "support" area but this is a link to a good starting point:
http://www.omega.com/section/thermocouples.html

 

LT

[cabako]

Good info there thank you!

[neilestrick]

If you're firing in reduction, I would put that thermocouple in a protection tube. Usually somewhere around 2- 2.5 inches into the kiln is sufficient.