VR Technology VR Series - Selecting Closed Circuit Gases and PO2 Set Point

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Selecting closed circuit gases and PO2 Set point

If you have purchased and installed the PIN for the closed circuit upgrade, you will

have a Closed Circuit option in your GAS SELECT screen. Press and hold both

switches to activate this.

Entering this mode allows the selection of a closed circuit decompression algorithm

and opens a CLOSED CCT screen. In this screen the gas mix you have selected is

displayed as a diluent (DIL). Change the diluent as required by a short push of both

switches then following the same procedure as outlined above for selecting and

adjusting an open circuit gas.

A selectable PO2 setpoint is also shown in this screen. With successive short pushes

of the left switch the PO2 will increment in steps of 0.05 bar. Once you have the

desired PO2 a short push of the right switch will confirm and take you back to the

Home screen (or Dive screen if you are diving). The P02 and the diluent will be

displayed there.

You can preset two different PO2 setpoints and switch between them during your

dive. To do this, re-enter the CLOSED CCT screen, select another PO2 and exit

again.

During your dive a long push on + in this screen will enable you to toggle between the

two setpoints.

The VR assumes that the PO2 selected is the PO2 that the rebreather will maintain as

its setpoint during the dive and it will calculate decompression based on this and the

diluent set. Your PO2 can change, especially on ascent and descent, and depending on

the characteristics of the rebreather and its operator. You are strongly advised to be

conservative with your PO2 selection. If you are diving and see a PO2 displayed

which is higher than the selected setpoint, this is because you are at a depth where the

diluent PO2 exceeds your setpoint. From the CLOSED CCT adjust screen, a long

push of both switches will select open circuit mode, where, in the event of a bailout

being required, you can select the gas you want to breathe in open circuit.

VR Dive Computer Operations Manual 2009 rev E 28/01/2009