+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13

Thread: AirZ O2 Question

  1. #1
    Mark Hilley firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver's Avatar
    Join Date
    Sep 2007
    Location
    gulfport, ms
    Posts
    836
    Kiss Sport

    Dolphin, Ray, Homebuild

    AirZ O2 Question

    I have a little problem that's bugging the hell out of me, and I was hoping some of you with experience on the AirZ O2 could help.

    The computer has an alarm for increased workload. It is set in the middle setting from the factory, but can be user adjusted from zero +/- a few steps each way using the Datatrak and memomouse. It can be changed from very sensitive to least sensitive.

    Every time I dive the alarm beeps at me. The "lungs" icon is shown in the display window on the computer. I have set the sensitivity to least sensitive, and it still does it.

    Here's the weird part....It beeps at me even when I know I'm not exerting much at all. I can be just hanging in the water or sitting on a rock perfectly still and it goes off. It seems to happen weather I'm actually breathing hard or not.

    I have always used another brand of computers and started using the Uwatec when I got the Rebreather, so I have only had a few years with the AirZ. I asked my LDS, who has used them for years if his alarms like this and he said "Sure it does......if I'm breathing too hard":D Lots of help

    I have two AirZ's and Oxy2's, so I tried the other ones just to see if it's a computer issue, and it does the same thing. I have tried bouncing the sensitivity setting from end to end, and still the alarm beeps at me. I know for a fact that I'm not working too hard, my numbers are good otherwise, and there are no other obvious issues.

    I've pretty much resigned myself that it's just a quirk I'll have to live with, but it still irritates the hell out of me. Anybody got any ideas?

    Thanks, FD.

  2. #2
    RBW Member Onephalynx is an unknown quantity at this point Onephalynx's Avatar
    Join Date
    Oct 2008
    Location
    San Diego
    Posts
    8

    Re: AirZ O2 Question

    Do youstill have the Air Z's?

  3. #3
    RBW Member curt is an unknown quantity at this point curt's Avatar
    Join Date
    Jul 2006
    Location
    Rockville, MD USA
    Posts
    120
    Rebreathers Australia Stingray

    Re: AirZ O2 Question

    FD,

    Don't know if this will help, but when I was diving my Dolphin with an Air Z O2 and Oxy2, I learned a few things about the way the alarms worked.

    The workload alarm does a comparison against the highest FO2 that it has seen during the current dive. Adjusting the sensitivity allows for a larger difference, but even the least sensitive setting was not able to handle the way I typically used my Dolphin (EAN45 on the 60% orifice).

    The way I worked around this was the following:

    - Last step of surface testing is to turn off gas flow and breathe the loop down to below 30%.

    - Turn on gas just before descent, then descend slowly enough that the bypass is not triggered.

    By following these steps, the measured FO2 slowly rises to the expected equilibrium value, and you can usually avoid the workload alarm.

    As always, YMMV...

  4. #4
    RBW Member Daddykins is an unknown quantity at this point Daddykins's Avatar
    Join Date
    Jan 2009
    Location
    uk
    Posts
    3

    Re: AirZ O2 Question

    The workload on the unit takes a reading early in the dive to give it a base figure to work to. This also applies to the open circuit units. I Would expect if you prebreathe the unit this is when it takes the figure on board. So you could try harder breathing on top before the dive.

  5. #5
    Mark Hilley firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver's Avatar
    Join Date
    Sep 2007
    Location
    gulfport, ms
    Posts
    836
    Kiss Sport

    Dolphin, Ray, Homebuild

    Re: AirZ O2 Question

    Thanks for the information guys!

    Curt, I think you may be on to something. I dive my Dolphin in the same way. Always on the 50% jet, adjust the mix for planned dive. Sometimes end up shallower than expected, which would explain the high FO2. If all it takes is to have a high/low FO2 spike that would definitely trigger the alarm. I wish I could just turn off the alarm.

    I usually let the unit sit for a while as I'm getting set up, so the loop is usually around 21-25% before I actually hit the water. I never race to the bottom, so if your method is correct, I should be in the general range.

    I'll try overbreathing on the pre-breathe too. It can't hurt. I'll give it a try and see what happens.

    Anyone with ideas, please keep it coming.

    Thanks, FD.:)

  6. #6
    RBW Member rebreatherdiver is an unknown quantity at this point rebreatherdiver's Avatar
    Join Date
    Mar 2008
    Location
    Northern Ireland
    Posts
    13
    Drager Dolphin

    Re: AirZ O2 Question

    Checked some of my Datatrak dive logs and the workload alarm comes on an off from time to time during the dive although I do not have a high workrate during the dive. Ah, this explains why my AirZ o2 beeps during my dives

  7. #7
    RBW Member grey-diver is an unknown quantity at this point grey-diver's Avatar
    Join Date
    Oct 2007
    Location
    West Yorkshire UK
    Posts
    35

    Re: AirZ O2 Question

    I usually dive with 32% EAN using either 40% or 50% jet. The warning comes when Fo2 drops to 24% or below. I assumed it was when loop Fo2 dropped to below a certain %age of the tank Fo2. The working hard warning brings additional deco penalties, which is not a bad thing. However, I now flush the loop whenever the warning occurs to raise the Fo2, and this gets rid of the warning.

  8. #8
    Banned sailor is on a distinguished road sailor is on a distinguished road sailor's Avatar
    Join Date
    Jul 2006
    Location
    Germany
    Posts
    373
    TR300c hCCR, Ray mCCR

    Dolphin, Inspiration Vision

    Re: AirZ O2 Question

    I believe the Uwatec computers are only good for SCR?
    Are you diving your unit mCCR?
    That might confuse the computer aswell.

  9. #9
    Mark Hilley firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver's Avatar
    Join Date
    Sep 2007
    Location
    gulfport, ms
    Posts
    836
    Kiss Sport

    Dolphin, Ray, Homebuild

    Re: AirZ O2 Question

    Quote Originally Posted by grey-diver  View Original Post
    I usually dive with 32% EAN using either 40% or 50% jet. The warning comes when Fo2 drops to 24% or below. I assumed it was when loop Fo2 dropped to below a certain %age of the tank Fo2. The working hard warning brings additional deco penalties, which is not a bad thing. However, I now flush the loop whenever the warning occurs to raise the Fo2, and this gets rid of the warning.

    It is definitely the workload alarm, not the loop going lean. My FO2 is great, just keep getting the %&$%$!! workload alarm. It's just irritating! You're probably right about one thing though, the computer likely adds deco time to increase offgassing.

    Thanks for your comments.

    FD:)

  10. #10
    Mark Hilley firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver is just really nice firemandiver's Avatar
    Join Date
    Sep 2007
    Location
    gulfport, ms
    Posts
    836
    Kiss Sport

    Dolphin, Ray, Homebuild

    Re: AirZ O2 Question

    Quote Originally Posted by sailor  View Original Post
    I believe the Uwatec computers are only good for SCR?
    Are you diving your unit mCCR?
    That might confuse the computer aswell.

    It's SCR only. I haven't been inclined to convert it yet. Maybe one day.


    Thanks, FD:)

+ Reply to Thread
Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts