Analog oven temperature meter?

[Starling]

So, I'm on the verge of assembling my first brick oven, and I'm inclined to include two high-temp sensors in the hearth and dome. But! My oven will be out in the yard without a nearby power supply and I don't much care for the aesthetic/accessibility issues that accompany digital meters.

So, my question:

Is there a solution that would allow me to use some/any kind of sensor embedded in the masonry at those two points, but which could then be wired to the two analog temperature meters mounted on the front face of the oven, WITHOUT an auxiliary power supply?

I've talked to Grainger, I've talked to Omega-- both tell me that my only option would be to use a high-temperature version of a meat/candy thermometer-- in this case embedded in the face of the oven with the long sensor mortared into a deeply-drilled hole that terminated within an inch of the oven interior.

Does this make any sense? Does anybody have a lead on a solution to this?

[Mingy]

I don't know if I understand the question. I went with an Omega Thermometer (HH306) and embedded a total of 4 thermocoupled in various places (thermocouples are really cheap). I believe the battery life on the thermometer is quite long, but you ave to keep it out of the rain.

One of my projects is to build a battery powered thermocouple based thermometer with a display which fits in a 4" weatherproof electrical service box. I intend to make it wirelessly accessible from my home PC network. Just for fun.

[roobqn]

I used a 6 position thermocouple from IMC Industries that is battery operated. While it is 6 positions, I only used three probes (dome, floor, insulation slab below floor). Here is a picture of it, I have since enclosed it with a wood box that has been weatherproofed. Battery has been in going on two years. It is easy to get to however whenever I need to change it.

[GianniFocaccia]

Hey Roobqn,

Thanks for sharing. What did your IMC 776X run you?

John

[roobqn]

Back then (May2010) it cost me 267.00 for the unit and 17.00 per thermocouple. Shipping was 17.00 as well.

[GianniFocaccia]

Thanks! The units on the IMC website look perfect for our application, especially the devices designed to monitor bread and pizzas.

[david s]

From my experience with thermocouples in use with kilns, the digital ones all tend to fail. But the old fashioned anologue ones never do provided you don't drop them. When heat is passed through the probe it generates a small electric current which runs through a sensitive meter which is calibrated to temp as the current is directly proportional to the temperature. It therefore does not need a power source. The digital variety has a battery or external power source to power the LCD and the internal circuitry.Anologue for me.

[david s]

I doubt whether you could buy an anologue meter for a thermocouple in the digital age, I'm sure they're all digital now. Ask a local pottery association if anyone has an old one they'de be willing to sell you.

[Sananguero]

I scored these at the family warehouse which used to be a surplus supply for industrial valves, instruments, and tubing. Plan to use two, one in the dome and one in the hearth. I am thinking about sinking these right into the vermicrete insulation, then cement/mortar coat the dome up to the face. Also there is a threaded thermocouple pipe cover that I wasnt planning to use to minimize the hole I would have to drill in the dome. The diameter of the cover looks to be about 1" while the diameter of the actual sensor is only about 1/4"

[Lburou]

FWIW, I'm using an infra red thermometer and it works just fine.

The reports by those who have installed thermocouples in their ovens vary, but, the consensus is that you will get used to your oven and not need all that data. The infra red thermometer, or, even the time to burn flour are adequate measures.

That said, do what makes you happy in your project.