how many thermocouples?

[RichC]

How many thermo couples should I install in my oven and whereabouts? I think it'll be a kit, igloo style? I assume 1 in the hearth centre, but should I install any more? Is there any point?
Also, should they be installed in thermowells or simply embedded in the structure?
Thanks
Richard

[Faith In Virginia]

Re: how many thermocouples?

What's the plan for your oven, Pizza , Bread, other stuff? The reason I ask is because most people agree that if all you want to do is Pizza or other stuff there is no reason to even have one thermocouple and a simple IR thermometer will get you going, and after you learn your oven you won't even need that much.

If you wanting to do bread that is a different story yet it is still debated, some like and some see no need.

I do a lot of bread and I have 6 thermocouples now that I have experience with my oven I could easily knock it down to three.

One in the floor 3/4 inch from the heated surface, One mid-wall 3/4 inch from the heated surface, and one on the outside of the mid-wall between the brick and the insulation. That gives me all I need to know. It can tell me how saturated my oven is and how many runs of bread I can bake before I use all my heat.

Hope that helps, Faith

[ShuttleAU]

Re: how many thermocouples?

+1 for IR thermometer

[mrchipster]

Re: how many thermocouples?

How many thermo couples should I install in my oven and whereabouts? I think it'll be a kit, igloo style? I assume 1 in the hearth centre, but should I install any more? Is there any point?
Also, should they be installed in thermowells or simply embedded in the structure?
Thanks
Richard

If you are going to do it make sure they can be removed, the sensors will need to be replaced at some point.

That said, I have made some very nice bread and many other things with just a cheap harbor freight ir thermometer, bought on sale for $22.00

If you are just doing pizza I do not think you need anything but your eyes and a light if it is dark.

Chip

[Tscarborough]

Re: how many thermocouples?

None, they are useful until you learn your oven, then superfluous. Spend 40 bucks for an IR gun and use it for 5 or 20 firings and then you don't need anything.

[Laurentius]

Re: how many thermocouples?

I'm in total agreement. 0!

[RichC]

Re: how many thermocouples?

Thanks guys, decision made

[kbartman]

Re: how many thermocouples?

RichC,
Oh bummer, I was enjoying the discussion hate to see it end so soon......I like gagets, think all the guests you could impress..........I'm wanting to incorporate thermocouples in my build was wondering what type of readout units have others used and where they located them?

[Faith In Virginia]

Re: how many thermocouples?

Here you go KB,

This is my meter High Accuracy Digital Thermometers
This is my switch Multiprobe Switchbox For Handheld Thermocouple Thermometers

I have 6 thermocouples

Two in the floor one at 3/4 inch from the surface and one 4 inch from the surface.
Two in the walls mid way up the wall 3/4 inch from the surface,one left one right.
One in the wall midway up 4 inches from the surface.
One in the wall midway up between the oven and the insulation 7.5 inches from the surface.

I just had one thermocouple go bad so be sure to install them in a way that can be accessed later for replacement if one goes bad.

Nice thing about my meter is I can unplug it from the thermocouples and keep it in the house and for my second oven all I'll need is the thermocouples and switch the handheld meter from one oven to the next.

[RichC]

Re: how many thermocouples?

Well KBartman, I may actually put 1 or 2 in. The one my refractory sells is this Digital Thermometer . I might just buy a few probes and install them as it should be very cheap. And then buy 1 digital readout like this, or even use my multimeter. Can anyone tell me, is it a Ktype probe or what? Also how do you guys fit them so they're replaceable? Thermowells aren't very cheap or is there some sort if DIY thermowell or sleeve that's made out of copper pipe or something, what's the best thermowell to use?

[kbartman]

Re: how many thermocouples?

Thanks for the info Faith. RichC Glad to see you?re still considering.

I have not done a whole lot of research to see what?s available and the associated cost. I notice on Utah beehiver?s build, he has placed tubing during the dome build process, I think that?s an excellent idea. I?m not sure if he has finished and what his final plans are.

I work in power generation industry and thermocouples are common place. There are many types of thermocouple. Type K thermocouple is one that should work fine. Usually thermocouple probes are housed in some type of thermo well. This keeps the probe safe from the process measured and allows the thermocouple to be removed easily. A common type thermocouple probe found on gas turbine generators consist of 1/16? stainless tube like probe in various lengths. The probe can be easily removed and reinserted. This probe is inserted in into stainless tubing with it terminating at the point inside the machine where the measurement is needed. The probe lead wires are connected to the extension wire and they continue to the readout instrumentation and controls. My plan is to use an inexpensive thermocouple probe of some sort. I have not found an inexpensive probe that will work in the tubing. With that being said push comes to shove I figure I can take inexpensive thermocouple extension wire and fabricate my own for pennies. I figure I should be able to get a digital read out for less than $75 not sure on a multiple selector switch.

I?ll let you all know what I figure out. I?m all open for any suggestions and or comments.

[david s]

Re: how many thermocouples?

Most people find that fancy temp measuring equipment is pretty redundant after a while as you tune in to how the oven behaves with the fire. It is rather incongruous to use electronic devices on an ancient oven. I find my stopwatch, observation and a little semolina flour on the floor surface is all I need for pizza and for bread or a roast a cheap air temp thermometer placed inside the oven is perfectly adequate. Thermocouples and IR thermometers are helpful when getting to know your oven, but when experienced you'll hardly ever use or need them.

[Faith In Virginia]

Re: how many thermocouples?

I love being the odd duck. I like and use my thermocouples all the time and don't find them incongruous at all. But then again I built my oven for bread and not pizza. I also do large batches of bread on a single firing so I need to know that I have enough stored energy to do that.

If all I was doing was pizza and a few loaves of bread I agree that thermocouples are not necessary. But still, if your a bit of a geek and like gadgets and need precise heating numbers thermocouples are cool.

[kbartman]

Re: how many thermocouples?

I love being the odd duck.

But still, if your a bit of a geek and like gadgets and need precise heating numbers thermocouples are cool.

Faith, I'll be geeky duck with you.......if that's ok

[boerwarrior]

Re: how many thermocouples?

KB,

I'm also in the geek club. I bought a digital thermometer on-line for $40- (nice big display because my eyes aren't getting any better as I get older!) It takes 2 type K thermocouples and you can easily switch to read either one. It came with 2 cheap thermocouples but I went ahead and bought 2 high temperature (1000 degrees centigrade) thermocouples on line with extra long leads for about $30. So I was $70 out the door with exactly what I needed. I can post of photo of the meter after I get home if it would help.

Neil