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Testo 320 question

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Hello all,

I have a 320 that was recently serviced at Testo. I was doing a combustion test the other day and noticed that the readings changed if I placed the analyzer in a horizontal vs vertical position.

I never noticed this before, but I usually find a good spot for it and leave it. The magnets aren’t the best and it recently slipped down a pipe and the screen landed on a draw off and cracked. So I’m a little more cautious as to where I place it now.

Anyone have any input on this? I haven’t called Testo yet, but I figured some real world input would be nice.

Thank you!

Taki,

Comments

  • Zman
    Zman Member Posts: 7,607
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    How much did it change? Have you checked to be sure the lines and filters are clean. I have the same model and will check the next time I use it.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    I wonder if in horizontal it's slightly pinching the tubes. I know Bacharach recommends vertical, letting the tubes hang, free of pinching or kinks.

    There was an error rendering this rich post.

  • ratio
    ratio Member Posts: 3,701
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    I had something similar with a Magnahelic, the readings changed if I moved the gauge. Chased it down to a drop of water in one of the lines—threw everything off.

    I was pulling my hair out for a while!

  • Takdashark
    Takdashark Member Posts: 3
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    They change quite a bit, over a percent. I swear it didn’t do it before! I called Testo and first the tech said it was out of calibration. But it was calibrated by them less than 6 months ago and has been used a dozen times on residential condensing gas boilers on tune ups.
    I did remove everything and check for water in the lines.

    Now I’m starting to question any adjustments I made to the last few systems I worked on.

    I’ll will update as thing go along. Thanks for the replies!
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    Do you have access (buddy?) to another analyzer where you can go side by side to check?

    There was an error rendering this rich post.

  • DZoro
    DZoro Member Posts: 1,048
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    I did have a older 320 do the same thing, I too was concerned. It is now my back up have a new 320. Never put the two side by side for a test. Will do no time for that this winter, maybe later will do a comparison. Just didn't trust it when I seen it do that trick, one needs to trust our test instruments, hence bought new.
    D
  • Takdashark
    Takdashark Member Posts: 3
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    I do have a access to buddies analyzer, but as mentioned above it’s trying to find the time to get together to do it.

    After another call to Testo I was told to replace the O2 sensor. I ordered one, if I don’t feel confident after that I will have to pull the trigger on a new one. Last time I sent mine out to Testo in Jan they had for a month. That’s too long to be without an analyzer, especially in the winter.