We are making a brick bread oven , also wood-fired. Do we realy need to install thermocouples, what benefits has anyone had? If we do, where can we buy them from in New Zealand? What about using a stainless steel thermometer that is placed in the oven as required?
Many thanks if someone has some answers.
Replies
Perhaps there is a mobile thermometer that could achieve this task ...temperatures during firing go very high...however the mobile thermometer may not be capable of providing a deeper level of temperature assessment, an indication absorbed heat in the fire bricks (rather than just surface heat). Firing an oven correctly is all about assessing that a satisfactory amount of retained heat has been achieved.
My experience is in side-flu Scotch ovens. Traditionally they used a thermometer which was exposed to the main chamber of the oven during firing, though on the opposite side to the fire and protected somewhat by a metal pipe housing. Alan Scott places several thermocouple thermometers during installations for his ovens. I will ask him for his opinion and report back.
Thinking aloud now...but I think that your idea of a stainless thermometer, during firing, might work if you house it in metal pipe / or a shield and attune yourself to how the subsequent readings indicate retained heat potential of your oven.
Different thermometers measure different things. I find I need hem all.
You need thermocouples or an embedded thermometer to measure the temperature in the brick, which represents the amount of heat stored. An oven thermometer measures the air temperature, and a laser thermometer measures the surface temperature of the brick. The surface temperature can vary quite quickly, for example if exposed to the fire or if cooled by opening the door or having cold dough in contact.
Ideally you need several thermocouples embedded in different places and different depths to give you a full picture. Thermocouples don' last forever so you need to embed them so that they both have good thermal contact and can be replaced, for example inside narrow bore conduit or copper pipe drilled into the brick and under the hearth from outside.
You might want to look at http://groups.yahoo.com/group/brick-oven where there is an active debate about thermocouples at the moment.
Alternatively middle of the dome, also about an inch in.
Eventually you experience and feel will guide you, but thermocouples are still useful, and cheap.
You could order them from Pyrosales and have them mailed over to NZ.
Cheers,
Gavin (Rosebud Australia).
We plan to instal it under the floor and have drilled a hole to insert in to the concrete. We salvaged a short piece of stainless steel tubing from my Dad's old dairy, which he was using for a garden stake and that wil be our conduit in case we need to replace the thermocouple in the future.
This weekend we are doing the hearth floor and hope to make a Xmas holiday project with our family all involved doing the oven part. I am hoping to light a small fire then and be able to perhaps bake some lavosh bread. Cheers Sheryl
Im looking for advice on what thermocouple to purchase for a wood fired oven im building any help, im in canada