Flue thermometer - piece of junk!

[turnkey4099]

I just stand next to my wood stove and within a second I can tell if it is too hot or too cold or just right.

John

I rely on my wife. "it's cold in here" (room thermometer showing 79).

Harry K

 

[turnkey4099]

That pretty much proves my point. You anti gadget guys are stuck in the stone age. Using a thermometer to gather data to quantify what is happening in a stove is the same as using any other scale. Sure you can do it without using the scale but it is easier, faster, more consistent and more acurate when you do. Accuracy depending on the quality of the gadget/tool.

But there are some things that do not need the accuracy of a "gadget". Stoves are one of them. I, do, however have on my stack

Harry K

 

[turnkey4099]

I was actually hoping someone would ask that so I could point out what a silly gadget an oven timer is.
Yeah, Mrs. Spidey uses the oven timer and it makes me laugh... for example, let's say she's making a cake. She puts the cake in the oven and sits down in front of the TV. After a few minutes she gets up and proclaims the oven timer is about to sound off, walks into the kitchen and stands there at the oven, watching the clock and waiting for the beep. After the beep she opens the oven door, sticks a toothpick in the cake and pulls it back out... after examining the toothpick she claims it ain't done yet, closes the door, and sits back down for a minute or two before removing the cake from the oven.

Why did she even set the timer in the first place??? She absolutely knew how much time had passed... she even walked in the kitchen before the timer sounded-off!!! Then she don't believe the timer anyway, checks the cake using the time honored toothpick method... then actually proclaims the timer was wrong!!! And then, when I start laughing she can't figure out what I find so damn funny, which makes me laugh even harder!!!

At least gadgets are good for something... they're good for a laugh when other people use them!!!

An oven timer is a necessity for me. Without the thing going off, I would forget I even had anything in there...yes it has happened when I even forgot to set it.

Now my truck is a tool. The car?


Harry K

 

[blades]

A tad of perspective on the flue temp. You said bed of coals stove top 175 ok now think about those nice red hot coals, as those are what I use to heat a piece of steel red hot ( think somewhere in the area of 1300 deg F, now the heat coming of those coals not being radiated away by the large thermal mass of the stove body is going up the flue. at the center of the flue yep its going to HOT, now as we progess to the steel sleeve that forms the flue Which is surrounded by cold air the temp at the flue's surface like the stove is going to be considerably lower.
With a infared gun you can pin point various temp spots say 175 on top of stove, glass will be 300( just a number for an example) oh and if ya got a blower running across the stove top then that reading is likely 150 degs or more low as well.

Another referance point: A good quality pyrometer will run in the $1k class, have specific calibration requirements and likely be +/- .0x%, so at $6.95 or 24.95 it is just a basic reference point/ KInd of like touching it with a finger to see how bad a blister ya get. as In: a little red=too cold, get a white blister- OK, Third degree burn-too hot. Flue pipe cherry red and sounds like a freight train, call fire department for Chimney fire. Stay warm, Chris

 

[zogger]

Yep! And I like a nice bed of hot coals :msp_tongue:



otstir:

Yep, me too! A hottie in a nice bed is a wunnerful thing...

 

[Steve NW WI]

A tad of perspective on the flue temp. You said bed of coals stove top 175 ok now think about those nice red hot coals, as those are what I use to heat a piece of steel red hot ( think somewhere in the area of 1300 deg F, now the heat coming of those coals not being radiated away by the large thermal mass of the stove body is going up the flue. at the center of the flue yep its going to HOT, now as we progess to the steel sleeve that forms the flue Which is surrounded by cold air the temp at the flue's surface like the stove is going to be considerably lower.
With a infared gun you can pin point various temp spots say 175 on top of stove, glass will be 300( just a number for an example) oh and if ya got a blower running across the stove top then that reading is likely 150 degs or more low as well.

Another referance point: A good quality pyrometer will run in the $1k class, have specific calibration requirements and likely be +/- .0x%, so at $6.95 or 24.95 it is just a basic reference point/ KInd of like touching it with a finger to see how bad a blister ya get. as In: a little red=too cold, get a white blister- OK, Third degree burn-too hot. Flue pipe cherry red and sounds like a freight train, call fire department for Chimney fire. Stay warm, Chris

Just to clarify, 175° was pipe surface temp about an inch away from the probe thermometer, not stove top temp.

 

[bucknfeller]

Sorry for turning your thread sideways Steve :msp_rolleyes:

















Well not really, but it sounded good

 

[Steve NW WI]

I'm suprised really. With a prime target thread like this, I expected more hooligan activity...

Had to put it out there anywho - ain't got many cutting pics to share this time of year.

 

[bucknfeller]

I'm suprised really. With a prime target thread like this, I expected more hooligan activity...

Had to put it out there anywho - ain't got many cutting pics to share this time of year.

Is that an invitation? I could post a link in a certain thread and......:msp_biggrin:

 

[Whitespider]

Hooligan activity??

Where??

I don't see any hooligans....

Hooligans on AS??

No way...... not hooligans.

You must be thinkin' of a different site.

Now... can we get back to the serious part of this thread... ya' know? Making fun of gadget users :yoyo:

 

[Whitespider]

Geee, I'm really sorry Steve... but it's just so darn hard to be empathetic...
I mean... it's a $12.oo gadget... a box-o-beer costs more.
But I do have a thought... for another 99-cents you could buy a fine-point felt-tip pen and put whatever numbers on the thing you want, in whatever location you want, thereby making it as accurate as you want :hmm3grin2orange:

 

[beerbelly]

Spidey, that tape measure is just a gadget. You could measure everything in paces if ya wanted to.

Don't forget our good friends the span, cubit, rod, chain, and link.

And for temperature we can always rely on "ouch, it's hot!" or "brrr it's cold!" :hmm3grin2orange:

Sorry....hooligan switch got flipped on...please carry on. :msp_wink:

 

[Highbeam]

When I bought my new stove, I picked up a SBI probe type thermometer. I was in a hurry to get the stove in and working, and just today got around to installing it.

It took me all of half an hour to figure out that this thing is about as accurate as a smoothbore musket at 1200 yards. My camera does a poor job of focusing on multiple points, but the needle is pointing at about 1100 degrees. I know the outer and internal temps are gonna be different, but triple? No way, no how.

A shot of my stove top thermometer, again, fuzzy, but within 25° of the IR gun reading:

This is the "overfire" that gave me the above readings:

While it bothers me a little that I bought a $12 piece of junk, it bothers me more that this is a tool that the stove makers recommend to keep your stove operating in it's safe range. Mine is way off to the high side, a novice burner would be mad as heck about a stove that wouldn't heat like it's supposed to being choked down to the "safe" range, and one off the other way would have worse consequences.

What I'm getting at here, is why would a stove maker (SBI in this case) put their name on a measurement tool that can't measure what it's supposed to? If I were in their shoes, I'd be selling a (likely more expensive) reliable unit or none at all.

Fyrebug - got any input here?

The probe thermometer might be slightly high, most are a hundred or two high at this range, but your equipment is not faulty. Surface temps of single wall pipe are half of the interior temps. Double wall pipe which you have adds another layer of insulating air and then another layer of steel which will easily drop that surface temperature by half again.

That's the whole point of double wall interior pipe. Raise interior flue temps and reduce outer skin temps. Your gauges are not faulty.

 

[Steve NW WI]

The probe thermometer might be slightly high, most are a hundred or two high at this range, but your equipment is not faulty. Surface temps of single wall pipe are half of the interior temps. Double wall pipe which you have adds another layer of insulating air and then another layer of steel which will easily drop that surface temperature by half again.

That's the whole point of double wall interior pipe. Raise interior flue temps and reduce outer skin temps. Your gauges are not faulty.

Sorry if the pics are misleading, that's singlewall pipe.

 

[Highbeam]

Sorry if the pics are misleading, that's singlewall pipe.

That's your problem then. Probe meters are only for double wall pipe. They measure temp based on the coil right behind the dial face (not the probe directly) and have a factor based on what the outer shell of double wall should be for a given interior temp. So your probe meter thinks that the outside of the double wall is really hot and is reporting a temp that is also much higher.

To measure flue temps of a single wall connector pipe you need a surface meter and double the reading. Your IR gun shows 350 so your internal flue temps at the time were only 700 which is fine but way under the operating temp limit of 1000 for class A.