Thermometer Choices

I would have to say that there is safety in numbers!
If you have 4 instruments that are reading very close to the same then mob rules
After doing this instrumentation thing as a career sometimes I get balled up in the details.
The thermocouples are very reliable the questionable part is the display that is interpreting the signal, with that said they are brand new and I would say they are accurate.
When I said we have a .05% tolerance where I work, I mean when I go out to calibrate an instrument in the field I am using upwards of $6500 dollars worth of equipment to verify the accuracy.
It is crazy, but that is what is required sometimes.
Love these threads
CS

coal stoker wrote:I would have to say that there is safety in numbers!
If you have 4 instruments that are reading very close to the same then mob rules
After doing this instrumentation thing as a career sometimes I get balled up in the details.
The thermocouples are very reliable the questionable part is the display that is interpreting the signal, with that said they are brand new and I would say they are accurate.
When I said we have a .05% tolerance where I work, I mean when I go out to calibrate an instrument in the field I am using upwards of $6500 dollars worth of equipment to verify the accuracy.
It is crazy, but that is what is required sometimes.
Love these threads
CS

I have some friends in the industry so I am going to see if I can get some instruments over to the house for a night ! what a fun experiment! For the record I have a hard time trusting cheap stuff but sometimes I am surprised

Smokeyja wrote:

coal stoker wrote:I would have to say that there is safety in numbers!
If you have 4 instruments that are reading very close to the same then mob rules
After doing this instrumentation thing as a career sometimes I get balled up in the details.
The thermocouples are very reliable the questionable part is the display that is interpreting the signal, with that said they are brand new and I would say they are accurate.
When I said we have a .05% tolerance where I work, I mean when I go out to calibrate an instrument in the field I am using upwards of $6500 dollars worth of equipment to verify the accuracy.
It is crazy, but that is what is required sometimes.
Love these threads
CS

I have some friends in the industry so I am going to see if I can get some instruments over to the house for a night ! what a fun experiment! For the record I have a hard time trusting cheap stuff but sometimes I am surprised

Yup.
My cheap Rutland magnetic is scary accurate for the stack temps in the narrow range that I normally run the kitchen range - low to mid 100 F.

But, just open the dampers for loading and it's gets further and further off as the temps climb above that operating range.

Paul

I have 3 4 channel thermocouple amps from Texas instruments and all the calibrations done in their lab as prototypes to build an evaluation board for their then new chipset for that job. Each board came with a calibration curve for each channel on all 3 boards. Now to search for an accurate display with a 0-5 volt input. I also have a large box of thermocouples with exposed junctions that are very fast and armor covered wires about 6 feet long.

I think the real R&D that needs to be done is with the ability to transfer heat and different materials and surface finishes that encourage the transfer. I keep wondering how a stove with the upper section made out of 5052 aluminum would work as much more heat transfer and while heat would anneal the material even at T0 it is more than strong enough and never have seen a temp that could come close to melting it. An interior thermocouple would settle that argument quickly. I have a bunch of other ideas as well that would transfer heat well enough to make a BB blush there are plenty of stones left un turned no matter how good they were then.

ddahlgren wrote:I have 3 4 channel thermocouple amps from Texas instruments and all the calibrations done in their lab as prototypes to build an evaluation board for their then new chipset for that job. Each board came with a calibration curve for each channel on all 3 boards. Now to search for an accurate display with a 0-5 volt input. I also have a large box of thermocouples with exposed junctions that are very fast and armor covered wires about 6 feet long.

I think the real R&D that needs to be done is with the ability to transfer heat and different materials and surface finishes that encourage the transfer. I keep wondering how a stove with the upper section made out of 5052 aluminum would work as much more heat transfer and while heat would anneal the material even at T0 it is more than strong enough and never have seen a temp that could come close to melting it. An interior thermocouple would settle that argument quickly. I have a bunch of other ideas as well that would transfer heat well enough to make a BB blush there are plenty of stones left un turned no matter how good they were then.

I can give you internal temps now with wood . It hasn't gotten cold enough to burn steady coal at the moment but I will give you whatever information I have as I read it . Tonight I will be restarting the fire with wood tonight . I will give you the internal temps but I think you are right about the aluminum top . The problem with the aluminum top would be too much heat transfer meaning the stove might not hold a fire longer when using low temps? Just something think about . What about the aluminum top combined with the cast iron skin? But your idea is very neat and I would like to see that happen! I think you should combined your ideas with a flu recirculating system like a base heater / burner . You could then attach aluminum to the base to pull heat out lower .

I will take any info you are willing to share! Comparing internal stove to internal stack would offer plenty. With stove surface and stack surface I would say you have all of it.

ddahlgren wrote:I have 3 4 channel thermocouple amps from Texas instruments and all the calibrations done in their lab as prototypes to build an evaluation board for their then new chipset for that job. Each board came with a calibration curve for each channel on all 3 boards. Now to search for an accurate display with a 0-5 volt input. I also have a large box of thermocouples with exposed junctions that are very fast and armor covered wires about 6 feet long.

I think the real R&D that needs to be done is with the ability to transfer heat and different materials and surface finishes that encourage the transfer. I keep wondering how a stove with the upper section made out of 5052 aluminum would work as much more heat transfer and while heat would anneal the material even at T0 it is more than strong enough and never have seen a temp that could come close to melting it. An interior thermocouple would settle that argument quickly. I have a bunch of other ideas as well that would transfer heat well enough to make a BB blush there are plenty of stones left un turned no matter how good they were then.

I've often wondered why, with it's higher heat transfer ability, an aluminum alloy wasn't used more in stove castings. Yes, it has a higher thermal expansion rate then cast iron, but that can often be compensated for in design as it was in early internal combustion engines that used both aluminum and cast iron - such as early Hispano aluminum engines with cast iron sleeved bore in an aluminum engine block .

In fact, aluminum was used extensively in the early auto industry by some manufacturers and to a lesser extent by the early aircraft industry. Plus, the technology for complex castings, both large and small, made of aluminum was there before WWI. And there were alloys that held up to the high temps and pressures of some early aluminum cylinder heads for internal combustion engines at least as early as the late 1920's for cars I work on.

Paul

you know a glenwood 6 or any of these round steel jacket base heaters/burners would be a good candidate to test with 5052 sheet . make it twice as thick as the steel gauge barrel which looks to be around 16-18 gauge ? maybe of you know better on that actual gauge I am just guessing and am not by my stove at the moment . So figure on making the aluminum sheet at least 1/8 or 12-10 gauge . This would be something easy without destroying any of the castings and if it didn't work out could easily be put back to normal . some of the bottom pans are broken and most un-repairable so these would be a good candidate for a stamped aluminum base to allow better heat transfer . I wonder how well 5052 would last being exposed to coal and wood ash /creosote . I have some different alloys of aluminum including some aircraft grade stuff. I may put some coal ash in it after doing a few a few heat cycles with a torch and see how it deal with corrosion .

and have I mentioned how amazing it would looked all polished out?

just killed the idea of the jacket out of 5052

http://asm.matweb.com/search/SpecificMaterial.asp ... =MA5052H32

melting point to liquid around 1200F ... would work for a heat seek though.

6061 is about the same as well.

copper would work as a skin though with a melting point of 1984F it also has a higher thermal conductivity

http://www.tibtech.com/conductivity.php

when the steel goes bad on my barrel I know what I want! Might have to look into the effects of the heat cycle on it though . Copper becomes brittle after a certain point.

While burning hardwood low I am running steady around 800°F in the firepot , which I am reading just below the flu outlet by the spark guard . The inside of the flu into the chimney is reading around 300°

Top of the G6 is 332°
The flu skin is 176°
The barrel skin is 363°

The bottom chamber on the G6, where the flu has is recirculated is 175°

I'm burning at .03 inches of water

If I burn a little warmer or ramp the fire up I will be at 1000°F or more in the fire pot .

These are avg. numbers that I see with wood since I have been burning this season. Next I will post all my coal numbers which will be more steady obviously .

Here is what I run it is in a drilled hole in the stack.

2001Sierra wrote:Here is what I run it is in a drilled hole in the stack.

Nice looking install! I have to ask where you got the 90 degree elbow with no seams to leak ash.

Smokeyja interesting numbers and look a lot like what I have found with internal stack very close to stove top though a little below stove top. I had a chat today with a friend in the casting business that is world class. He has cast parts others thought impossible and does them to perfection as long as you can afford him. Pouring a complicated shape for an oil tank that holds 3 1/2 gallons at 0.04 thick in 356 aluminum is no simple trick. He verified 1200F the end of the earth for any grade aluminum and might sag if any pressure on it before that. Sad as it is 448% better at heat transfer than steel. Brass will go over 1700 and 205% better than carbon steel so a possibility there.

I need to email him later to get some pointers on where to find heat transfer, melting points and heat fatigue strength of various materials. Aluminum is wildly better but begs the question how hot does the stove get if wildly out of control to get a worst case scenario. Brass while only twice as good might be a fall back position.

Smokeyja wrote:just killed the idea of the jacket out of 5052

http://asm.matweb.com/search/SpecificMaterial.asp ... =MA5052H32

melting point to liquid around 1200F ... would work for a heat seek though.

6061 is about the same as well.

copper would work as a skin though with a melting point of 1984F it also has a higher thermal conductivity

http://www.tibtech.com/conductivity.php

when the steel goes bad on my barrel I know what I want! Might have to look into the effects of the heat cycle on it though . Copper becomes brittle after a certain point.

Check the two links I posted earlier they have a lot of info. That's why I thought copper would be a better solution. I don't think you will ever over fire a copper top to 1900°F and so it should stay nice and maluable . Brass will certainly turn brittle once heated . I have forged brass and it's something hard to work with because it becomes so brittle once a it cools .

The Budenberg was stupid easy to adjust ! All the gauges are reading the same now . I'm going to adjust the magnetic ones at some point .

Smokeyja wrote:

Smokeyja wrote:just killed the idea of the jacket out of 5052

http://asm.matweb.com/search/SpecificMaterial.asp ... =MA5052H32

melting point to liquid around 1200F ... would work for a heat seek though.

6061 is about the same as well.

copper would work as a skin though with a melting point of 1984F it also has a higher thermal conductivity

http://www.tibtech.com/conductivity.php

when the steel goes bad on my barrel I know what I want! Might have to look into the effects of the heat cycle on it though . Copper becomes brittle after a certain point.

Check the two links I posted earlier they have a lot of info. That's why I thought copper would be a better solution. I don't think you will ever over fire a copper top to 1900°F and so it should stay nice and maluable . Brass will certainly turn brittle once heated . I have forged brass and it's something hard to work with because it becomes so brittle once a it cools .

Josh,
Are you annealing it after heating ? If so, how ? Has it turned pink-ish in color after cooling down ?

Paul