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Proper instrument to measure offset pressure of gas valve

I have a Fieldpiece digital dualport manometer but am concerned about the accuracy for sensitive negative pressure gas valve offset adjustments.

I read a post a while back about using a magnehelic gauge with a zero center and very small scale. Can someone point me to where I might purchase one? I believe it was a Dwyer but they make so many insturments, I'm unsure which to get.

Thanks in advance.


  • Ted_9
    Ted_9 Member Posts: 1,718
    Me too

    I know the Dwyers are good. I also saw a small Testo digital one that is good for negative gas valves like the ones you find on the Buderus GB142.


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  • Ken D.
    Ken D. Member Posts: 836

    Dwyer's Magnahelic in the correct scale is a very accurate and dependable instrument.
  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291
    Testo 506

    I have a couple and find them very accurate. The 506 will do + or - and differential and it's sensitive enough to read W.C." to the third decimal. I've checked it against my Mag and found it to be spot on every time. I know for a fact that Chuck Shaw uses that instrument in his work at HTP.
  • John McArthur_2
    John McArthur_2 Member Posts: 157

    My fieldpiece digital reads to 1/100th of an inch. I'm just unsure of how accurate any of the digitals are.

    Which Dwyer are you guys using? I think the 2300 looks like the one to get, but was unsure if it was safe for combustible gases.

    Thanks guys.
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