I've found the Gehaltemeter to be the gold standard for DO and CO2 measurement. The orbispheres I've used all had problems with repeatability and plugging. The plugging isn't an issue with clean worts but anything that has any heavy matter in it is going to result in unreliable measurement, unless you've got wort to spare and don't mind using some percussive maintenance on it. The measurement was also flow dependent - hence, the repeatability issue and variability from one person to the next.
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Sean Flynn
Solutions Beverage Consulting
Missoula MT
(303) 521-9674
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