To develop a blending plan, begin by
entering enter the values for your
Starting and Target Mix. In this
example, a diver finishes with 800 PSI
of trimix 16/40 and needs 3000 PSI of
trimix 26/17 for the next dive. In this
case, no bleed down is required and the
Blender adds 291 PSI of oxygen to a
pressure of 1091 PSI to the existing
mix. When you analyze the gas at this
stage of the process, you should see an
FO2 of 38.4%. The Blender
then adds 190 PSI of Helium to a
pressure of 1281 PSI. The result of the
gas analysis at this stage should yield
an FO2 of 32.7%. The mix is
then topped to 3000 PSI with air
yielding a cylinder of trimix 26/17.
Fill order can be changed by toggling
the Fill O2 First Switch.
Switching to “off” changes the fill
order to Helium first followed by Oxygen
and the Top Off Gas.
override the top off gas fraction of
Oxygen (FO2) and fraction of Helium (FHe)
on this screen. Valid values range from
0% to 100%. If it is not mathematically
possible to create a blending plan with
the parameters you have set, you will
receive a warning.
Switching Bank Mix
to “on” calculates a blending plan using
your bank mix. When “off” 100% O2 is
used in the blending process.
With Real Gas
“on” van der Waals equations are used to
calculate the blending plan. When off
ideal gas formulas are used.
“on” and “off” changes the calculations
and displays between imperial and metric
units. Cost values are converted between
cubic feet and liters.
Once you have changed the parameters of
your starting and target mix, press the
Calculate Button. This will
update your mixing plan.
You can “top off” a mix by setting the
Top Off Mix Switch to “on.”
In this example, if you switch the
top off mix button to "on" and press
calculate, your blending plan will show
the result of topping 800 PSI of 16/40
to 3000 psi with Air (21%).
To switch from the blending instructions
page to the blending information screen
on the iPhone and iPod Touch, swipe your
finger across the screen as if you were
turning the page in a book. This
advances between pages.
On the blending information page, you
can compute gas volumes and costs for
single tanks or doubles. You can also
switch between Retail and Shop Cost
calculation set values. You can also
override the default cylinder
specifications here. To calculate the
blending cost for a high pressure Steel
120, change the pressure and volume
values to 3500 and 80.
When you exit the app, the scenario you
are working on is saved and it is
redisplayed the next time you access the
To reset all values to the
default values, double tap on the