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***jradomski*** · 19th January 2006, 23:18

Before anyone asks about check valves and the absence of them it is for a reason..

Anyone calibrating a Meg that has a valve on the water trap is inducing this error.. That means the PO2 is always higher than what is displayed. The "2 point" calibration makes this even worse since AIR was not set under the increased pressure..

All check valves have some required cracking pressure.. for small diameters the best units usually have around .3 psi of cracking pressure, Thats an average error of 2%.. Most check valves are worse than this so the error will e greater.

19th January 2006, 23:18	#2 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,004	Re: Accurate PO2 Calibration Before anyone asks about check valves and the absence of them it is for a reason.. Anyone calibrating a Meg that has a valve on the water trap is inducing this error.. That means the PO2 is always higher than what is displayed. The "2 point" calibration makes this even worse since AIR was not set under the increased pressure.. All check valves have some required cracking pressure.. for small diameters the best units usually have around .3 psi of cracking pressure, Thats an average error of 2%.. Most check valves are worse than this so the error will e greater. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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