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  • 1.  DO Calibration Liquid

    Posted 06-25-2024 14:02

    Does anyone know of a readily available liquid with a known dissolved oxygen level (if such a thing exists) that can be used to run through a Hach Orbisphere 3100 to verify sensor calibrations? I recently calibrated our meter using the manufacturers SOP with 99.999% N2 but it would be nice to have a liquid with a known DO level to run through it to verify that the calibration is correct. 



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    Andrew Sanderson
    Quality Manager
    Sly Fox Brewing Co
    Pottstown PA
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  • 2.  RE: DO Calibration Liquid

    Posted 06-26-2024 13:52
    Edited by Josh Waldman 06-26-2024 18:06

    You can purchase dissolved oxygen standard solutions/tabs for a zero point calibration. In the past (also with a 3100) I have used canned macro beer injected with a known volume of air but I remember it being a pain to get to work. Here is a post detailing the process in the old Tap Into Hach blog:

    https://tapintohach.wordpress.com/2013/07/31/pictorial-instructions-for-creating-a-tpo-validation-standard/



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    Andrew White, P. Biol
    Quality Manager/Brewer
    Blindman Brewing
    Lacombe AB
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    Original Message


  • 3.  RE: DO Calibration Liquid

    Posted 06-26-2024 18:03

    Hach makes a zero calibration liquid.  It is basically just a strong metabisulphite solution and they recommend it for calibrating polarographic (membrane-type) hand-held O2 probes.  I don't know of a calibration liquid like the one you are looking for, but you can get "span gas" which is N2 with a measured percentage of O2 included.  I bought a small cylinder of 0.25% O2 from Liquid Technology of Apopka, FL (407) 292-2990.  I used it for verification of the range of interest, but not for calibration.  I believe it is possible to conduct a two-point calibration on the Orbisphere 3100, but I don't think Hach really recommends it.

    You might also try conducting a TPO validation test, as described in Chaz Benedict's weblog.  See his September 30th, 2013 post in Tap Into Hach.  I tried it but did not get expected results, and never determined if that was because of my sloppy technique, the calibration of the meter, or something else.



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    Cullen Dwyer
    Brewer/Cellar/QA
    Finestkind Brewing
    Westminster MA
    (978) 874-9965x1160
    Brewer/Cellar/QAFinestkind BrewingFinestkind BrewingBrewer/Cellar/QABrewer/Cellar/QA
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    Original Message


  • 4.  RE: DO Calibration Liquid

    Posted 06-27-2024 15:14

    Hi Andrew,
    This is Chris from Profamo.  One of the companies that we represent, Trace Measurement, make a verifier for DO, CO2 and N2.  The verifier will provide a water solution with a very precise amount of DO (+/- 2 ppb typically).  If you would like more information, please reach out to me directly.  
    Cheers



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    Chris Nimptsch
    President
    Profamo Inc
    Rancho Palos Verdes CA
    (941) 284-7990
    [chris@profamo.com]
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    Original Message


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