optional, single

—

Inside the <gasdefinitions> section happens the definition of the different breathing gases used by the <owner> of the UDDF file.

<gasdefinitions> stands after the <divesite> section and before <profiledata>.

The only elements inside <gasdefinitions> are <mix>, and <tankdata> (both can be repeated any times). First all <mix> elements have to appear, then all <tankdata> statements. This is necessary to support referentiations inside the latter to breathing gases declared in the <mix> elements.

The <gasdefinitions> section mustn't be given. If <gasdefinitions> doesn't occur, the executing software has to set air as the breathing gas. Of course, a breathing gas consumption calculation cannot be performed in case of a missing <gasdefinitions> section.

<uddf>

<mix>, <tankdata>

<mix>, <tankdata>

<gasdefinitions>
    <!-- all breathing gases used -->
    <mix id="oxygen_pure">
        <name>pure oxygen</name>
        <o2>1.000</o2>
        <n2>0.000</n2>
        <he>0.000</he>
        <ar>0.000</ar>
        <h2>0.000</h2>
    </mix>
    <mix id="air">
        <name>air</name>
        <o2>0.210</o2>
        <n2>0.790</n2>
        <he>0.000</he>
        <ar>0.000</ar>
        <h2>0.000</h2>
    </mix>
    <mix id="nitrox6040">
        <name>Nitrox60/40</name>  <!-- Nitrox 60 % N2, 40 % O2 -->
        <o2>0.400</o2>
        <n2>0.600</n2>
        <he>0.000</he>
        <ar>0.000</ar>
        <h2>0.000</h2>
    </mix>
    <mix id="trimix">
        <name>Trimix</name>  <!-- Trimix 15 % O2, 40 % N2, 45 % He -->
        <o2>0.150</o2>
        <n2>0.400</n2>
        <he>0.450</he>
        <ar>0.000</ar>
        <h2>0.000</h2>
    </mix>
    <tankdata id="air_1">
        <!-- air filled 15 litre tank, fill pressure at beginning 200 bar, -->
        <!-- breathing gas consumption volume 12 litres/minute -->
        <mixref ref="air"/>
        <tankvolume>0.015</tankvolume>
        <tankpressurebegin>20000000.0</tankpressurebegin>
        <breathingconsumptionvolume>0.0002</breathingconsumptionvolume>         <!-- units are [m^3/s]! -->
    </tankdata>
    <tankdata id="air_2">
        <!-- another air filled tank... -->
        <mixref ref="air"/>
        <tankvolume>0.01</tankvolume>
        <tankpressurebegin>20000000.0</tankpressurebegin>
        <breathingconsumptionvolume>0.0003333</breathingconsumptionvolume>      <!-- units are [m^3/s]! -->
    </tankdata>
    <tankdata id="nitrox_tank">
        <mixref ref="nitrox6040"/>
        <tankvolume>0.01</tankvolume>
        <tankpressurebegin>220000000.0</tankpressurebegin>
        <breathingconsumptionvolume>0.00025</breathingconsumptionvolume>        <!-- units are [m^3/s]! -->
        <tankmaterial>aluminium</tankmaterial>
    </tankdata>
    <tankdata id="o2_tank">
        <mixref ref="oxygen_pure"/>
        <!-- the following statement requires information inside <diver><buddy> -->
        <!-- <tank id="tank_O2_pure"> about this kind of tank -->
        <tankref ref="tank_O2_pure"/>
        <tankvolume>0.008</tankvolume>
        <tankpressurebegin>20000000.0</tankpressurebegin>
        <breathingconsumptionvolume>0.0002</breathingconsumptionvolume>         <!-- units are [m^3/s]! -->
        <tankmaterial>steel</tankmaterial>
    </tankdata>
</gasdefinitions>