Removal procedure:

1. Install the Transmitter on HP Port of 1st Stage

Use a 1st stage with two HP ports so that a backup analog SPG can also be installed. Ensure the o-ring is present and free of debris when installing the transmitter. O-ring is -012 size, We recommend Viton® material for replacements.

2. Position the Transmitter on Same Side as Perdix

Range is approximately 3’ (1m). Angle to side or point slightly forward. For complex installations, a short high-pressure hose may be required.

3. Open Tank Valve

The transmitter will automatically turn on when it detects pressure. Likewise, the transmitter will automatically turn off after 2 minutes of no pressure. Therefore, to turn off the transmitter, close the tank valve and bleed the pressure by purging your 2nd stage. For now, leave the valve open

4. Enable AI on the Perdix 2

On the Perdix 2, navigate to the System Setup > AI Setup. Change the AI Mode setting to On.

5. Pair the Transmitter

Each transmitter has a unique serial number etched on its body. All communications are coded with this number so that the source of each pressure reading can be identified. Pair the transmitter by going to the Tx Setup menu option, and selecting T1. Turn on T1, then enter 6-digit transmitter serial number into the T1 Serial # setting. You only needed to set this one, as it will be permanently saved in the settings memory.

6. Add an AI Display to the Main Screen

The main screen will not show any AI displays until they are added. Alternatively, the AI info can be left off the main screen, and then accessed by pressing the right button twice.

7. Ready to Dive

The AI feature is now ready to dive. If you see “No Comms” messages, ensure the tank valve is turned on and the transmitter-to-Perdix distance is less than 3 ft (1m). The AI setup process is the same for the Petrel and Nerd 2.


GTR is similar to NDL. GTR is the time, in minutes, that you can remain at the current depth until a direct ascent would result in surfacing with the reserve pressure remaining. GTR is based on your current SAC (surface air consumption) rate. GTR (and SAC) are not measured while on the surface and not shown for the first few minutes of a dive, until enough data is collected for estimates.


The current tank pressure is shown in PSI or Bar.

The bar graph provides quick visualization of the pressure.

Warnings and status may be displayed: