Retro-Fitting Thermo couples

[Martin B]

Has anyone got any advice about retro fitting thermocouples after an oven has been built? We were going to go with just a laser thermometer for hearth reading but have now decided that we want to know the core temperature at three different depths.
We have an A/S style oven. Presumably we can drill from the bottom of the hearth base to the depths that are required.
Cheers
MB

[Ron Rathburn]

My only advice is to try to stay away from any steel you may have in the slab (rebar?). I have one TC 1" from the hearth surface, one TC under the firebrick on the hearth, and will have another under the portland/vermiculite layer (Hole is there but I have not yet installed the TC.

Based on advice from Alan Scott, I put them close to the center of the hearth. I also put 3 TCs in the Dome, 1" from the heat chamber, on top of the dome firebrick, and the last one at the surface of the concrete cladding. Alan suggested that the dome TCs be put half way between the hearth and the top of the dome and centered front to back. Hope this helps.
If you want to sort through a lot of pictures for mine you can see my build pictures at picasaweb.google.com/ronrath28/BrickOven.

I did put mine in during the construction phase but don't see why drilling holes after wouldn't work. Some talk of installing glass or metal wells so the TCs can be easily replaced if they fail. My thinking is that by the time they fail I will have the "feel" of my oven enough to operate it without the TCs. The laser thermometer you have will still be handy to measure surface temps. My final test before putting bread in the oven is to toss in a little flour and see if it turns browh in about 13 seconds (don't ask why not 12 or 14 seconds, I just know this works for my oven, lol ). If it passes this test the bread bakes nicely and doesn't scorch.

Best of luck,
Ron