Dolphin Limiting Factors

[wedivebc]

Calculate it for yourself, tell me if my math is off.

I don't know what PPO2 you are basing it on. Assuming a PPO2 of 1.6 and for a single daily exposure you have over 7 hrs before you reached 850 OTUs.
It is highly unlikely a RB diver would plan a dive at 1.6 PPO2 and even if you were using an SCR with 32% at 130ft the gas in the loop would be something less than 1.6.
Now if you were talking about CNS clock you would have to limit your PPO2 to 1.3 to get a single dive exposure of 3 hrs

 

[Thalassamania]

Now if you were talking about CNS clock you would have to limit your PPO2 to 1.3 to get a single dive exposure of 3 hrs

There you go. That's what the discussion was about:

Drager Dolphin

0 to 17 msw 125 min with 60% O2 and 40% N2
• 0 to 22 msw 95 min with 50% O2 and 50% N2
• 0 to 30 msw 67 min with 40% O2 and 60% N2
• 0 to 40 msw 47 min with 32% O2 and 68% N2

What is limiting the bottom time for these times? Is it the scrubber or the tank size?

If it is the tank size and I put a bigger tank on it what is the biggest size i could put on?

What is the scrubber duration?

How much gas would i need to push the duration to 3 hours using the 32 flow?

 

[gtlaqua]

:can anyone tell me where i can buy the new extendair retrofit scubber for the drager dohlpin instead of sodalime it takes a extendair cartridge . i live in maryland.

thanks in advance

 

[solanabezo]

I would like to ask if any one in the list use a oxy2 and a alladin air z or x? Is there another available sensor in the market for the dolphin? Do they still make the Oxy 2?
Thanks in advance for your help.

 

[MauiScubaSteve]

My IANDT instructor and training manual talked about 4 hour max duration at near rest, IIRC. 3 hours 45 minutes was considered safe max for gentle recreational type diving.

 

[mobula]

I sold my 2 Dolphins Oxy2 included this year because of limited time and other issues. Oxy2 was nerving. There are more options: Shearwater or Vr3 (or VR2) connected with a cable. For the Shearwater adapters check out www.tecme.de.

This was on my own risk, do not copy....:

40% mix with 50% nozzle: oxygen level never dropped below 22%, mostly it was around 28-32%, sometimes more in the circuit. Or 36% with 40% nozzle. Max possible dive time with a 8 l tank: 180 min, so scrubber is not the limitation. About me: my weight is 103 kg, height 189 cm, lung volume 7,3 l, strong legs, longest scrubber time with some kicking 480 min, my wife 60 min longer.

I did 100 fantastic SCR dives on the Maldives, around Socorro, in Thailand and Malpelo. I will come back with CCR or SCR again. I sold my rebreathers because Draeger stopped production of the Dolphin, I bought the Sony EX1 and my beautiful daughter entered planet earth

 

[bletso]

Scrubbers are independent of depth, their duration is a function of CO2 production and temperature. The Dolphin scrubber is rated at 3 hours, that's depth independent. If you're willing to push it to the limit and have found a way to carry enough gas ... you can get 3 hours.

The two 45's you see in the pic were not for SCR but for OC bailout on a deep dive. The O2 on my left was for metabolic duration. The unit is MCCR. At least you copied my good side.

Since that pic, we have changed our configuration several times and place more importance on off board supplies.

BTW, Scrubber duration does show degradation at depth and with colder temps. Refer to the USN Dive manual. Also, in a memo from Draeger dated Aug 2003, the duration for the Dolphin was extended to 250 mins. Keep in mind, the biggest limiting factor to scrubber duration is YOUR VO2, and temperature, then depth.


Dale