It is essential that a LST understands how to establish a ppO₂ in a saturation environment.

Establishing a PPO2
EXAMPLE

Pressurise to 90msw using 16 % and 2 % HeO2. 

–Maintain  a pO2 of 400 mbar.

Initial blowdown using the 16%  until a desired depth to switch to the low mix.

          (400required PPO2  –  210current PPO2 )  –  (90msw x  2%) ÷  (10% – 2%)  

=          190 -180 ÷ 8 = 10 ÷ 8

   =              1.25 msw on 10 %

• IMCA D022. Guidance for Diving Supervisors Manual, Chapter 2, Section 15-17, Pages 18-20
• IMCA D050-Minimum Quantities of Gas Required Offshore

Now proceed to the quiz: > > > > >