Results 1 to 4 of 4

Thread: Some common formulas

Hybrid View

  1. #1
    Registered Users
    Join Date
    Feb 2007
    Posts
    432

    Default Some common formulas

    Here are some common formulas. For those tec's out there, this is old stuff.
    I post for the reference as well as for those who are curious. For the more
    seasoned diver who if itchy to learn more about the physics of diving, this
    will help out too. Look up the achronym online, ie END or MOD, SAC, TGC
    (on how to calculate TGC), etc... to get a better idea of what and why. Of
    course, get training as a Advanced Nitrox and/or Trimix diver to learn more.

    As one becomes more techical, computers are good, but planning is important.
    Computer programs available for purchase will help, but when you're out in the
    field and there is not computer, knowing the formulas will come in handy.

    This is not a comprehensive list of formulas, just some I choose to write
    down. Why these particular formulas? Because they are the ones that came
    to mind when writing this post.

    EAD: Equivalent Air Depth
    D: Depth
    T: Time
    TGC: Total Gas Consumed
    FO: Fraction of Oxygen
    TOD: Target Operating Depth
    MOD: Maximum Operating Depth
    END: Equivalent Nitrogen Depth
    tEND: Target END
    SAC: Surface Air Consumption
    RMV: Respiratory Minute Volume
    RCWP: Rated Cylinder Working Pressure
    RCV: Rated Cylinder Volume
    EAD: Equivalent Air Depth
    FN: Fraction of Nitrogen
    PO2: -or- PPO: Partial Pressure of Oxygen

    FN = (EAD + 33) * .79 / (D + 33)

    FO = PO2 / (( D / 33 ) + 1)
    ie. FO = 1.4 / (( 132 / 33 ) + 1

    TOD = (( PO2 / FO2 ) - 1 ) * 33
    ie. TOD = (( 1.4 / .32 ) - 1 ) * 33

    MOD = (( PO2 / FO2 ) - 1 ) * 33
    ie. MOD = (( 1.6 / .32 ) - 1 ) * 33

    END = ((tEND + 33) * .79) / ( D + 33)

    SAC = TGC / ( D * T )

    RMV = (( SAC / RCWP / RCV ))

    EAD = ((( FN * ( D + 33 )) / .79 ) - 33

    I'll post more later....

  2. #2
    Registered Users doczerothree's Avatar
    State
    Florida
    Country
    USA
    Join Date
    May 2008
    Posts
    7

    Exclamation

    Good stuff!
    Tôi khá có nó và không cần nó so với cần nó và ot có nó!!

  3. #3
    SMN Publisher The Publisher's Avatar
    Country
    USA
    Join Date
    Apr 2007
    Posts
    2,231

    Default

    Lars, when you post more we'll edit your original post to add them all together, thanks for the info.
    SMN Publisher

  4. #4
    Registered Users
    Join Date
    Jul 2012
    Posts
    1

    Default

    Safety is first thing for divers, you can go with the most of the instructions followed by professional divers, learn everything before going to start diving.

Tags for this Thread

Posting Permissions

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