off board gas inspiration

[punt]

Good morning,

I have a question that troubles me. Asume a dive with dil 11/35 trimix and I have an empty oxygen tank after a while. As a bailout I carry a 15/35 and a ean 70. Can I plug in the ean 70 as a replecament for my empty oxygen without any other considerations? The solenoid will thake my setpoint up as I put this in the computer(inspiration/vision), normally 1,3bar so this will not be a problem but wath about the decompression obligations. I presume this will not change a lot considering I am already ascending.

Sincerally regards,

Punt

 

[ScubaAl]

If your plugging into your O2 manual add on the exhale counterlung you will have to maintain the sp manually. The solenoid won't do it.

Al

 

[punt]

Hallo Al,

thank you for the respons,ofcose very stupid off me,but further there will be no implications?

Sincerally regards,
ron

 

[Doppler]

Ron: Your Vision electronics will have computed your decompression obligation based primarily on your set-point and secondarily by the mixture of inert gas filling that vacant partial pressure. In the scenario you describe -- if I understand correctly -- your "oxygen" now contains about 30 percent nitrogen, and as such there should be no decernable effect on your deco obligation... because flying the unit manually, you should have no issues mainintaining a 1.3 bar set point during most of your ascent. However, in the shallowest stops, 1.3 bar will not be possible with a 0.7 bar gas... no oxygen flushes!

All the best.

 

[punt]

Hi,

Thank you for your reply. Is really helpfull.
Thanks,
Ron

 

[Doppler]

A small clarification: I may have been caffeine deprived when I posted.

The oxygen setpoint's influence is secondary to the vacant partial-pressure when decompression obligation is computed... it's the quantity of inert gas that drives the equation... essentially the same, but different to what I wrote. Still equals same end result. Sorry.


Sent from my iPad using Tapatalk

 

[punt]

Thank You for your reply, I am still learning and need good advice. My instructor has explained me different deco software and asked me to make a real nice dive planning to 90m/300 feet with a nice team bailout only I had to use v-planner and had to calculated a gradient factor 40/90. I suppose he is fooling around because I think there is no way to use GF on a vpm based model. Please advice.

Sincerely regards,
Ron

 

[DepthCharge]

You are correct. Gradient Factors are with Buhlmann. NOT with VPM-b
John

 

[punt]

Thank You all.

Best regards,
Ron