Double Check your Stove Thermometers (now with picture)

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PunKid8888

PunKid8888

Feeling the Heat
Nov 25, 2008
312
South East NH
Well I had an older thermometer (left) and a newer one (right) the older one I had on the stove top and then newer one was 12inches up on the flue. I was getting some interesting numbers, really High Stove Top temp and low flue temp. So I finally decided to double check them.

stovetemp.jpg


Its tough to see but the left (older) one is reading a little bit more then 600F while the right is reading about 475F and as you can see buy my gun its reading 458F. So if you do not have a IR gun to check your thermometer accuracy at least buy two and confirm they are accurate to each other. I will Be going out and buying another thermometer tonight and then running it along side the others to see if I have two that are the same.


the Best news is I was extremely impressed at the heat this stove throws at 600F, but in reality it was only at about 475F, So now I can't wait till it gets real cold and get the stove up to a real 600F
 
Yup, I have in my showroom right now, on a piece of stove pipe a thermometer that is reading 180 degrees. The stove hasnt been lit in 6 months. Now that's efficient.
 
Yup, having a similar issue with mine....one reads 550 and the other reads 460-470...seems like quite a range....guess I need a third one and will have to average all three :)
 
Can you guys see the picture?
 
No can see the picture.

We had 3 or 4 thermometers. Finally threw a couple out. Best we've found so far are the ones from Woodstock. Worst was one purchased from Lehman's.
 
nope, gone
 
You can adjust them some. Just grab the part with the coil and turn the outside ring. After you get it correct you can tap on the ribbit and it will not move. I had to do 2 of mine and the now both read as what the gun saids.
Don
 
N6CRV said:
You can adjust them some. Just grab the part with the coil and turn the outside ring. After you get it correct you can tap on the ribbit and it will not move. I had to do 2 of mine and the now both read as what the gun saids.
Don
Click to expand...

I think thats the issue....we know that you can adjust them, but try to figure out which one is correct.
"Hey Honey...add one of those infra red camara gun thingees to my santa list" :)
 
atomichawg said:
You need a minimum of 10 stove top thermometers, 2 flue thermometers, and 2 IR thermometer guns. Average all 14 readings. ;)
Click to expand...

What sample rate should I use - 10,000Hz just in case there are rapid fluctuations?
 
ya ive had different reading between 2 different ir guns too. china cant make 2 things the same anymore.
 
Any how do you know that your IR gun is accurate? Do you have 2 guns? just kiddin
 
Boil some water, aim the IR thermometer at the boiling water. check temp. calibration with boiling water surface temp
 
TomB said:
Boil some water, aim the IR thermometer at the boiling water. check temp. calibration with boiling water surface temp
Click to expand...

I think you need your altitude correction to make it perfect :)
 
Got the Condar Chimgard stovepipe thermometer to use on stovetop as dealer suggested. Ordered the Medallion from Condar as the product info tech at Condar said Chimguard wasn"t callibrated for stovetop use. Medallion info says it can be used as both. I don't know how it can work for both if different callibrations are needed. Had them both side by side on top of soapstone and they read identical all nite. Took the chimgard back. Anyone else use the Medallion? Can I hang my hat on this one?
 
strawman said:
Got the Condar Chimgard stovepipe thermometer to use on stovetop as dealer suggested. Ordered the Medallion from Condar as the product info tech at Condar said Chimguard wasn"t callibrated for stovetop use. Medallion info says it can be used as both. I don't know how it can work for both if different callibrations are needed. Had them both side by side on top of soapstone and they read identical all nite. Took the chimgard back. Anyone else use the Medallion? Can I hang my hat on this one?
Click to expand...

I hope so, as mine arrived today...
 
A man with one thermometer knows what the temperature is, the man with two never does.
 
pgmr said:
A man with one thermometer knows what the temperature is, the man with two never does.
Click to expand...

A man with three may actually have an idea, I wonder how my stove would radiate heat with 25 stuck to it?
 
pgmr said:
A man with one thermometer knows what the temperature is, the man with two never does.
Click to expand...
very well said !
 
I have one thermometer...IT"S ME ! if I am warm the stove is hot...
 
ilikewood said:
Any how do you know that your IR gun is accurate? Do you have 2 guns? just kiddin
Click to expand...

That's no joke. Just because the IR gun is high tech and electronic does not mean it will always read accurately. For example, the IR ear canal thermometers have much higher variation in indicated temperature than a properly used sublingual (under tongue) thermometer.

IR temperature measurement is fraught with difficulty. Two objects with exactly the same temperature, but different surface colors or textures will often read very differently to an IR device. The different surfaces have different "emissivity", which means that they radiate a different amount of energy at a given temperature.

I would imagine that if a manufacturer wanted to supply an IR gun specifically for the stove market, they would calibrate it for a matte black painted surface. How well it would read on a shiny enamel, or glass, or any other surface is uncertain.
 
grommal said:
ilikewood said:
Any how do you know that your IR gun is accurate? Do you have 2 guns? just kiddin
Click to expand...

That's no joke. Just because the IR gun is high tech and electronic does not mean it will always read accurately. For example, the IR ear canal thermometers have much higher variation in indicated temperature than a properly used sublingual (under tongue) thermometer.

IR temperature measurement is fraught with difficulty. Two objects with exactly the same temperature, but different surface colors or textures will often read very differently to an IR device. The different surfaces have different "emissivity", which means that they radiate a different amount of energy at a given temperature.

I would imagine that if a manufacturer wanted to supply an IR gun specifically for the stove market, they would calibrate it for a matte black painted surface. How well it would read on a shiny enamel, or glass, or any other surface is uncertain.
Click to expand...


shiny or glass is bad for ir to read! a matt is best i believe..
 
TomB said:
Boil some water, aim the IR thermometer at the boiling water. check temp. calibration with boiling water surface temp
Click to expand...

This is not an accurate way to test an IR thermometer. The gun could be reading the steam coming off the water or the bottom of the container etc. When I was in the food safety business, we started using IR thermometers to check product temperatures. We had to prove to the government that the IRs were accurate on a daily basis. After a discussion with the manufacturers the following procedure was developed. Heat the water to just under boiling (about 180) get a mercury thermometer and stir the water rapidly with the mercury thermometer while shooting the IR. Shoot the vortex of the water not the thermometer or the container.
This is the cheapest way to check calibration without expensive equipment.
 
TomB said:
Boil some water, aim the IR thermometer at the boiling water. check temp. calibration with boiling water surface temp
Click to expand...

That should work in theory...but only by the stroke of luck that water has the same emissivity as the black paint on the stove ~.95 If you boil in a stainless or anodized aluminum pot, you'd get a different temp looking at the pot itself.

The only other thing I see - all IR guns field of view is actually a 'cone' shape. Generally the sensor has a 10-15 degree field of view and anything in view is averaged for the temperature reading. The laser denotes the center of the cone, not an actual point where the temperature is measured. In this instance, the IR gun looks to be far enough away - and the laser close enough to the thermometers - it's likely portions of both thermometer cases are in the 'field of view' of the IR gun - and are giving a slightly lower temperature because they are cooler. Though it's probably close enough :)

The field of view could actually be something like:
 

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  • field of view.jpg
    field of view.jpg
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strawnman, have you even try to locate each of them , one on top , and the other en the pipe? just for the curiosity of knowing if there is the same temperature on top of the stove or 13 inches above, on the tube.
 
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