Oxygen sensor for a continuous blending system

[scubapeter]

After years of partial pressure blending, I am looking to switch to a nitrox stick. I mostly use 32 percent so the pros of continuous blending outweigh the cons. I have two oxycheq expedition oxygen analyzers that I would like to use for continuous blending. Does anyone know of a way to remote the sensor from this particular analyzer? I have only used it with the sensor mounted inside of the unit. Looking to avoid any unnecessary purchases.

I am also interested to know if anyone has personal experience with using wiffle balls in lieu of the more traditional baffles. In theory, they would produce a great deal of turbulence.

My compressor is a Bauer Capitano, it does now and always has used synthetic oil. It has a p0 primary filter and a Lawrence Factor Hyper filter as a secondary.

Thanks in advance for your comments and opinions

 

[NAM001]

wiffle balls work great,,,,, I use an oxycheck el-cheapo to monitor the blending content

 

[NAM001]

PM sent

 

[RayfromTX]

I found an old teledyne O2 sensor with the sensor removed on eBay with a new sensor for 125$. I would go that route again.

 

[aviator8]

I cant comment on the specific oxycheck but they are probably pretty easy to remove. I picked this one up fot my Cootwo at a good price.

US $29.6 |Free Shipping 1PCS the UK CITY Oxygen gas sensors AO2 ptb 18.10 ao2 CiTiceL oxygen sensor ao2 ptb 18.10 100%NEW STOCK-in Sensors from Electronic Components & Supplies on Aliexpress.com | Alibaba Group

 

[Chris H]

I'm using an old KISS display from my rebreather with an R-22 sensor also from the rebreather. As others have mentioned, the golf size wiffle balls are working well in my Nitrox Stick. It didn't take very many of the balls to work. Think 6-8, not a pipe full of them.

 

[clownfishsydney]

I don't use an oxygen sensor as I found that once I had worked out the necessary PSI needed on the oxygen cylinder for a certain %, then it is accurate enough to set and forget. All I do after the fill is test the tank to check %. Always very close to what I planned.

 

[RayfromTX]

As long as everything stays the same I can see that working but in a compressor setup things can change. Anything that changes the amount of air pulled in or the amount of gas pumped can change the ratio. I monitor the gas as it is pumped. I listen for changes in the sound of the system in operation. Last week I heard (through my hearing protection) a shift in the sound and immediately moved to determine the source. The first thing I looked at was the monitor and it was at 45% and climbing. I turned off the compressor immediately.

In this case the cause of the change was that the intake hose had slipped off of the compressor intake and that had made the sound change. With no air being pulled into the compressor but the compressor still running the O2 continued to flow into the stick raising the reading on the sensor. There was no real danger in this case as long as I breathed the rich mix out of the stick and hose before reconnecting and starting the compressor back up.

My point is that a filter obstruction will lead to a change in the mix(richer). A leaky valve or anything that reduces the intake of the compressor will change the mix(richer). A leak in the intake hose will change the mix(leaner at the compressor but unstable and richer at the sensor). I believe monitoring the mix entering the compressor is a safety issue.