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Combustion Analyzer Calibration

Alan (California Radiant) Forbes
Alan (California Radiant) Forbes Member Posts: 4,568
in THE MAIN WALL

My newest analyzer is a Testo 300 which I bought because I got tired of replacing expensive sensors every year, but the Testo needs to be sent in to the factory and calibrated every 2 years which means a couple of weeks without an analyzer and I can't work without one. So, I purchased another Testo 300 to have while the other one is being serviced.

Maybe I'll go into the analyzer rental business when other hydronic installers around me need to send in their machines.

8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 18,704

    It's a PITA but Testos are pretty good

  • captainco
    captainco Member Posts: 830

    I calibrated analyzers for my customers for 30 years. I never found one offl more than 10% even if they hadn't been calibrated for 4 or 5 years. The only sensor that needs calibration is the CO sensor, the O2 self-calibrates every time you turn it on. That every 2 years is just to dig into your pockets.

    I know CYA but if you knew how to use an analyzer it could bebe off 50% of the CO and never miss a problem. CO sensors last for 5 to 10 years easily. How often do home alarms get calibrated?

    To make sure the CO sensor works just stick it in any flame for 1-2 seconds. If it jumps to 100ppm and higher, it is good. If you have another analyzer or know someone else with one, check them in the same flue together. They won't read the same CO but they will be within 20-40ppm of each other. The O2 sensors will be within .1 to .5 of each other.

    The worst unit I ever tested was off 30ppm when measuring with test gas and it just came back from factory calibration.

    mattmia2Alan (California Radiant) ForbesRobert_H
  • mattmia2
    mattmia2 Member Posts: 14,394

    so basically it was ok then someone made it way off while trying to calibrate it…

  • captainco
    captainco Member Posts: 830

    Yes the manufacturer!!

  • HydronicMike
    HydronicMike Member Posts: 161

    True Tech tools calibrates analyzers. The last few times I sent it to them I have mine back in less than a week. The first time I sent it Bacharach and they had it 3 weeks.
    And you can use a discount code and get 6% off.
    I think Captain CO has one, or you could use getschooled.

  • captainco
    captainco Member Posts: 830

    Yes

    Trutech is the best for calibration. Coupon "NCI2025".

    But not necessary but every 2-3 years at most.

    HydronicMike
  • JMWHVAC
    JMWHVAC Member Posts: 94

    I purchased a Testo 310 this year. (Not my first Testo.) Before long, while in use, it went flunky. Readings seemed to be jumping around and the O2 reading would drop went I moved it from vertical to horizontal. Soo, I filled out the Testo form to return it, asking for warranty repairs and calibration. They still charged me for calibration. But the real kicker is, as before, in atmosphere the O2 reads correctly but drops a percent or two when I move unit from vertical to horizontal. THAT does not inspire confidence even tho it seems steady when testing. But I have an up-to-date calibration sticker on it!! Can I trust it? What would you do?

  • captainco
    captainco Member Posts: 830

    Does it drop from 20.9 to 20.8 or 20.9 to 19.9? Can you compare the readings with another analyzer?

    They shouldn't charge for calibration in warranty.

  • JMWHVAC
    JMWHVAC Member Posts: 94

    Just did some checking with it and either it's worse than when it 1st came back from "calibration" or else getting worse. If you zero the sensors while vertical then put it horizontal, right now it is dropping to 15.2% O2. Of course, if you zero it horizontal then put it vertical it goes off the scale displaying +++. Seems fairly consistent as long as you don't change the position in which it was zeroed. In the menu it says, "Last Maintenance 5/12/25" which is odd because I purchased it May 9 and the "calibration" was recently. My confidence in Testo service has been diminished.

  • captainco
    captainco Member Posts: 830

    Testo has had some bad units in the past. I would make them replace it with a new one. I think that would be less expensive than the bad press on the media.

    Your unit is bad!

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