Is this Flue Temp Probe Full of "It"?

[pen]

I love the hot tub test and the fat test. I only wonder if since the coil is above the water/oil that the heat rising from the liquid is heating the coil. I would expect condar to design this probe so that the coil is in ambient air and not in the steam which is of course hotter. I am quite certain that the air temp around that coil will have huge effects on the coil as shown by simply blowing on the coil with lung power.

I'm holding on to hope but am slowly starting to believe that these meters are crap.

How can we adjust them? Any word from Condar yet?

I emailed Condar at about 1:30 in the Afternoon Friday. By the close of business I had 2 different emails from them and confirmation that I'd here from their chief tech guy on Monday (he took off early Friday).

The communication has been top notch. I explained what I was experiencing and sent pictures as well. here is what they have replied with so far

This first communication is what the Marketing Director Mike Whitt CC'd to me as he passed it on to the Plant Supervisor, Carolyn

Carolyn –

I know that Rutland thermometer readings represent a compromise between stovetop and surface temps but I can’t explain the 900 degrees on the Fluegard. Any ideas?

Here is his 2nd email

The Condar Company has extensively tested our competitor Rutland’s thermometer and learned that it’s indicated "optimal operating zone" is a one-size-fits all compromise between what's recommended by manufacturers for stovetop use (400 to 600 F) and what's recommended for stovepipe use (230 to 475 F).

Regarding the FlueGard reading 900 F, our tech guy left early today so I can’t give you an answer about that until Monday. Our plant manager (Carolyn) would prefer we seek his input before replying.

Regards,

Mike Whitt

 

[begreen]

Ok, I just tried our Condar on the gas cooktop with the probe directly over a low flame. The probe was placed so that a full 2" of it was heated. After 5 minutes the thermometer was reading 775 °F, the IR reading on the probe itself was 803 °F.

 

[Peter B.]

However, that doesn't explain the large discrepancy when it is properly mounted on a flue pipe. It seems something is seriously wrong with this batch. My Condar probe is the old style with a solid black face. It's readings seem to consistently correlate with the stove top temps

If it's a bad batch, it's been 'bad' since this time last year when I bought the thermometers I posted about previously in this thread.

I was reluctant to bash Condar then (and never used their name in a post I made here at the time), but there weren't any other posters correlating what I'd found.

Now, however...

I just can't come up w/ any way to give credence to anything this thing is reading.

Condar does not guarantee accuracy... or even accuracy within +/- degrees, so I guess they're 'covered'.

But I consider I have about $75. invested in thermometers I can't trust to be accurate within 250* or so... which is a pretty wide margin.

I honestly think Condar needs to either work on quality control or make some <explicit> statements on how their thermometers are to be used (e.g. single/double wall flue) and what realistic expectations for accuracy they offer.

Again, I used one of their flue probes for all of twenty years, and came to rely on it. But I don't feel like I can rely on their current offerings.

Peter B.

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[pen]

Ok, I just tried our Condar on the gas cooktop with the probe directly over a low flame. The probe was placed so that a full 2" of it was heated. After 5 minutes the thermometer was reading 775 °F, the IR reading on the probe itself was 803 °F.

Just tried to do the same myself but my IR thermometer wouldn't read the probe tip. I think it's too small an area for mine.

Sounds like I'd trust yours though. And since that's the case...........

You in the mood to make some tea ?

If so, you then you can stick the end in the boiling water and see what you get. From what I did, the steam doesn't matter. So an open pot or kettle would be fine.

Since my IR won't keep up, that seems like the only way we can do this apples to apples or probe to probe. (hmm. probe to probe just doesn't sound appropriate :ahhh: )

pen

 

[Peter B.]

BeGreen's probe and my old (trusted) one may be - if not the same vintage - then the same model (# 3-19)... black dial.

I still trust my old one for a greater accuracy than _any_ of the new thermometers I bought.

Wish I could find another identical pair of the old model... and use them for another twenty years.

Peter B.

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[pen]

Funny thing is the box only says that they are good for about 4000 hours of use

pen

 

[Peter B.]

Funny thing is the box only says that they are good for about 4000 hours of use

Which - at 8,760 hours per year - might get you through a single Wisconsin heating season.

--

'Brewing some tea' now... report in a bit.

Peter B.

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[begreen]

BeGreen's probe and my old (trusted) one may be - if not the same vintage - then the same model (# 3-19)... black dial.

I still trust my old one for a greater accuracy than _any_ of the new thermometers I bought.

Wish I could find another identical pair of the old model... and use them for another twenty years.

Peter B.

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Yep, our SandHill stove top thermometer is now 30 years old and still accurate within 5 degrees.

 

[Peter B.]

My 'tea test' was inconclusive, I'd say... with about an inch and a half probe length immersed in boiling water, my old (3-19) flue probe and the new (3-39) flue probe (which replaced the 3-19) read <about> 400*... within 50*-100* of one another.

In the kitchen gas stove burner flame test, the new probe read about 750*; the old about 600*.

Anyways...

I'll be curious what Condar has to say.

Peter B.

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[Todd]

I just checked my Fisher that's burning as I type. Single wall pipe. The Condar magnetic thermometer is reading about 340 °F , the thermocouple probe is reading about 550 °F ,
I checked the Cnondar with a digital surface probe and it read about 310 °F .
(BTW the pic is an older one taken when the stove is not running.)
It sure looks like your Condar probe is reading high.
I think a digital probe is the way to go.

I think if we all want accurate measurements we all need something like Wess has set up. Thermocouple probes are much more accurate than the spring dial types which are more suited to be used as a rough guide.

 

[DanCorcoran]

If I remember correctly from my Navy electronics training, analog measuring devices are truly accurate only near the middle of their range. I don't know (but doubt) if this applies to digital devices.

 

[pen]

My 'tea test' was inconclusive, I'd say... with about an inch and a half probe length immersed in boiling water, my old (3-19) flue probe and the new (3-39) flue probe (which replaced the 3-19) read <about> 400*... within 50*-100* of one another.

In the kitchen gas stove burner flame test, the new probe read about 750*; the old about 600*.

Anyways...

I'll be curious what Condar has to say.

Peter B.

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Well, it is at least good to know that mine isn't the only one to read high in boiling water.

pen

 

[mikepinto65]

All this is making me and my two Condar thermos feel dirty!
Looking forward to hearing the techs response.....this would definitely explain my higher than most flue readings.

 

[Troutchaser]

I just installed the Condar probe into my double wall about two weeks ago. It will go from 0-1200deg. in ten minutes if I leave everything wide open. I thought that was normal, now I'm wondering if it's actually that hot.

If I did what the manual stated and filled up with kindling and then small splits and ran wide open to establish a coal bed, the Condar would indicate a melt down-I suspect-maybe even send out a 911 to the fire department. I do have to trust it somewhat though. No other choice.

 

[Peter B.]

Condar does not guarantee accuracy... or even accuracy within +/- degrees, so I guess they're 'covered'.

Actually, I was wrong... at this page on Condar's site:

(broken link removed to http://www.condar.com/probe_meters_dir4use_woodstoves.html)

... which outlines directions for use of the FlueGard (3-39), is the flat statement:

"When properly installed, the FlueGard accurately reads flue-gas temperatures, with an error margin less than 5%."

So... one might reasonably (like to) expect that to be true.

--

Incidentally, here:

(broken link removed to http://www.condar.com/stovepipe_meters.html)

... it's stated that:

"Long-stemmed probes give you the most precise and immediate temperature readings, for either single or double-wall stovepipe.

(The bold type is Condar's.)

Peter B.

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[Troutchaser]

Their site says the end of probe should be centered inside of the flue. I do not do that. I'll try it and see what the difference is. I just thought you stuck the sucker in flush to the pipe. Don't think that tidbit was on their packaging.

 

[Todd]

Their site says the end of probe should be centered inside of the flue. I do not do that. I'll try it and see what the difference is. I just thought you stuck the sucker in flush to the pipe. Don't think that tidbit was on their packaging.

I wonder if you can cut them down? It's a 4" probe which would make it center on an 8" pipe. Cut an inch off and it should be center in a 6" pipe.

 

[Troutchaser]

Their site says the end of probe should be centered inside of the flue. I do not do that. I'll try it and see what the difference is. I just thought you stuck the sucker in flush to the pipe. Don't think that tidbit was on their packaging.

I wonder if you can cut them down? It's a 4" probe which would make it center on an 8" pipe. Cut an inch off and it should be center in a 6" pipe.

Who goes first?

 

[Todd]

Their site says the end of probe should be centered inside of the flue. I do not do that. I'll try it and see what the difference is. I just thought you stuck the sucker in flush to the pipe. Don't think that tidbit was on their packaging.

I wonder if you can cut them down? It's a 4" probe which would make it center on an 8" pipe. Cut an inch off and it should be center in a 6" pipe.

Who goes first?

I know someone that already did it with a Condar cat probe for his WS Keystone, (rmcfall) and he said it works fine. https://www.hearth.com/talk/threads/47694/

 

[WES999]

I think what needs to be done is to install a Condar probe and thermocouple side by side in a actual stove pipe, and run the stove from 0 °F to say 1000 °F and record the the temps from both and compare them.

If anything the Condar should read a little lower than the thermocouple as the response time is slower than for a thermocouple.

Anyone have an extra Condar they would like to see tested?
I could test them both and post the results.

 

[Todd]

I cut mine down to a 3" probe so it's smack dab in the middle of the pipe. I still get the same high readings, doesn't make any difference. This is on sigle wall pipe. 1st pic is in the bypass mode, the internal really takes off and is more than double the external temps. 2nd pic is about 1 hour after engaging the cat the internal settles down to just about half the external.

 

[Peter B.]

1st pic is in the bypass mode, the internal really takes off and is more than double the external temps. 2nd pic is about 1 hour after engaging the cat the internal settles down to just about half the external.

My experience has been that higher temps (above 500*) are more likely to produce greater inaccuracies...

Peter B.

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[Todd]

Another thing to point out in my 2nd picture is with the magnetic external thermometer I'm barely in the good burn color coded zone which starts at 250, in fact after a couple hours it usually drops below. The internal probe I'm right in the middle of the good burn zone.

 

[begreen]

Anyone have an extra Condar they would like to see tested?
I could test them both and post the results.

Looks like pen has a flock of them. Maybe he can send one to you for verification?

 

[pen]

I think what needs to be done is to install a Condar probe and thermocouple side by side in a actual stove pipe, and run the stove from 0 °F to say 1000 °F and record the the temps from both and compare them.

If anything the Condar should read a little lower than the thermocouple as the response time is slower than for a thermocouple.

Anyone have an extra Condar they would like to see tested?
I could test them both and post the results.

PM me your address and I'll mail the one I have w/ a damaged face to you. If it gets crushed in shipping (again) no harm no foul.

pen