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Is this Flue Temp Probe Full of "It"?

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by pen, Jan 21, 2010.

  1. pen

    pen There are some who call me...mod. Staff Member

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    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

    Here is his 2nd email

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  2. begreen

    begreen Mooderator Staff Member

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    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.

    Attached Files:

  3. Peter B.

    Peter B. Feeling the Heat

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    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...

    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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  4. pen

    pen There are some who call me...mod. Staff Member

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    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
  5. Peter B.

    Peter B. Feeling the Heat

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    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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  6. pen

    pen There are some who call me...mod. Staff Member

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

    pen
  7. Peter B.

    Peter B. Feeling the Heat

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    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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  8. begreen

    begreen Mooderator Staff Member

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

    Peter B. Feeling the Heat

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    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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  10. Todd

    Todd Minister of Fire

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    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.
  11. DanCorcoran

    DanCorcoran Minister of Fire

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    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.
  12. pen

    pen There are some who call me...mod. Staff Member

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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
  13. mikepinto65

    mikepinto65 Minister of Fire

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    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.
  14. Troutchaser

    Troutchaser New Member

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    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.
  15. Peter B.

    Peter B. Feeling the Heat

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

    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:

    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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  16. Troutchaser

    Troutchaser New Member

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    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.
  17. Todd

    Todd Minister of Fire

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    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.
  18. Troutchaser

    Troutchaser New Member

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    Who goes first?
  19. Todd

    Todd Minister of Fire

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    I know someone that already did it with a Condar cat probe for his WS Keystone, (rmcfall) and he said it works fine. http://www.hearth.com/econtent/index.php/forums/viewthread/47694/P0/
  20. WES999

    WES999 Minister of Fire

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    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.
  21. Todd

    Todd Minister of Fire

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    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.

    Attached Files:

  22. Peter B.

    Peter B. Feeling the Heat

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

    Peter B.

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  23. Todd

    Todd Minister of Fire

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    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.
  24. begreen

    begreen Mooderator Staff Member

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

    pen There are some who call me...mod. Staff Member

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    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

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