thermocouples... same o same o

[dmun]

A brick wall that's hot most of the way through will stay hot and radiate heat for a long time. One that's hot on the surface will cool down quickly.

[ricocamus]

Originally Posted by dmun

A brick wall that's hot most of the way through will stay hot and radiate heat for a long time. One that's hot on the surface will cool down quickly.

OK, think I am beginning to understand.

The objective, then, is to get high temp (900) on the surface and in the brick. If you do that, then you can bake pizza all night long! Because the hot bricks will keep the surface temperatures hot.

[CanuckJim]

Rico,

Depends entirely on what type and how much cooking or baking your want to do. For a pizza bake of an hour or so, surface temps are all you need. If, however, you want multiple bakes, or you have added additional mass for heat retention over time, then deep brick or mass temps are very important. My oven is high mass, and I do multiple bread bakes over six to ten hours, so mass temps are just as important as surface temps. Next, when the mass has dropped to acceptable levels, I'll put in the roast or the chicken or the....

Jim

[ricocamus]

Originally Posted by CanuckJim

Rico,

Depends entirely on what type and how much cooking or baking your want to do. For a pizza bake of an hour or so, surface temps are all you need. If, however, you want multiple bakes, or you have added additional mass for heat retention over time, then deep brick or mass temps are very important. My oven is high mass, and I do multiple bread bakes over six to ten hours, so mass temps are just as important as surface temps. Next, when the mass has dropped to acceptable levels, I'll put in the roast or the chicken or the....

Jim

Hmmm, getting more complicated but more interesting as well. Now I think I have one more item to add to the buy list.

Is it just me or do these projects really have a way of growing on their own. Sort of like pizza dough in the rise stage . . .

[jcg31]

Sorry to put you guys through this again, but I have flipped on the thermocouple issue and am now contemplating it once again. I have searched all the posts and get the fact that I should be looking at K type thermocouple, but I don't see much out there on a preferred display. I would be looking for a wall mount (that I would enclose using CJim's approach) with four inputs, data tracking would be cool so a port out would be great but not essential. Anyone have any preferences?

Also (great timing) my dome is up, so in placing a thermocouple in the floor am I better coming in through the soldier course and floor brick (and how far in do I need to come to be meaningful), or up through the concrete and vermicucrete?

Thanks for any help,

Jim

[asudavew]

Originally Posted by jcg31

Also (great timing) my dome is up, so in placing a thermocouple in the floor am I better coming in through the soldier course and floor brick (and how far in do I need to come to be meaningful), or up through the concrete and vermicucrete?
Jim

Great question! I just figured I would go from under the hearth, through the concrete and verm layers...
But it sure would be a lot easier just to go through the side and into the floor bricks.
And I don't know why it wouldnt work, unless you wanted to know the floor temp right in the middle of the floor.
I think I will go through the side....

[wlively]

My floor TC is inserted through the side of the floor. I built the dome on top of the floor, so where the edge of the floor was exposed I drilled a 9" hole, pointed at the center of the floor, and put my thermocouple in there. It does not measure the center of the floor, but I do get decent readings which jive with the temp gradient across my dome. I think it is a good compromise in placement, not "the perfect spot" but is easier to install and route wiring.

As for meter. If you want to read multiple TC's at the same time you either have to get a rotary selector switch or a multi-input meter, neither of which is very cheap. You don't really need to see all the temps at the same time. The temp change is moderated by the thermal mass, so it is not very fast. Much easier to save the $$ and get a cheaper meter and then just swap plugs. Swapping plugs only takes an extra 5 seconds. I bought the hand held digital meter that takes 2 K-type inputs for about $75. If I were to do again, I would buy the combo IR gun that also reads K-type TC's and have the capability to do both in one and spend less $$.

[jcg31]

Originally Posted by wlively

As for meter. If you want to read multiple TC's at the same time you either have to get a rotary selector switch or a multi-input meter, neither of which is very cheap. You don't really need to see all the temps at the same time. The temp change is moderated by the thermal mass, so it is not very fast. Much easier to save the $$ and get a cheaper meter and then just swap plugs. Swapping plugs only takes an extra 5 seconds. I bought the hand held digital meter that takes 2 K-type inputs for about $75. If I were to do again, I would buy the combo IR gun that also reads K-type TC's and have the capability to do both in one and spend less $$.

Can you send me some product links? I found this one "technika.com/Sper/s800024.htm". What think ye of this solution?

[asudavew]

Hey Wade.

How many thermos do you have, and where did you place them?

I was thinking of putting one in the floor, in the top of the dome, and one all the way through for air temps?

Do I need one for air temps?

Jim,

Here is a link Wade sent me for a nice little unit.
Might want to check it out.

Low Cost Infrared Thermometer with Adjustable Emissivity


I found an older unit that looks brand new on Ebay for under thirty bucks. It is the J-type, but goes up to 1200f. It has one probe that came with it, and I ordered 2 more.
You may want to give Ebay a try.

Dave

[wlively]

Originally Posted by jcg31

Can you send me some product links? I found this one "technika.com/Sper/s800024.htm". What think ye of this solution?

Here is what I bought, looks like it went up $10. You can see a picture of it in action on my oven post.
Mini Thermometer — Moderately Priced - Ideal for Education, Training and Demonstration Programs

The link you posted looks like a fine meter, but unless you have the $$ to burn, or are going to use the oven commercially the extra $$ are not really worth it, IMHO.

As I continue to learn my oven's characteristics, I don't really use the TC's very much anymore. I can now cook pizza by color and feel pretty easily.