Poseidon SE7EN User Manual
Appendix 3 Page 124
4. Pre-Dive Procedures with a Poseidon SE7EN
enabled for Decompression Diving
It is possible to determine whether a rig is configured for decompression diving by examining
the ceiling indicator during the pre-dive routine. The ceiling indicator will be blank for a standard
rig and be lit flash for a SE7EN enabled for decompression diving.
48m/60m/100m Trimix
Figure 3-43:
Helium confirmation screen
at test 51, showing the question of helium
fraction content in the diluent gas tank.
Figure 3-44:
Oxygen confirmation screen
at test 52, showing the question of oxygen
fraction content in the diluent gas tank.
5. Switching batteries
If a rig has been configured with a gas mixture other than air on a SE7EN using a 48m, 60m
or a 100m battery, and then a 40m Deco battery or Recreational 40m battery is then inserted
into the rig, the user will be given a special prompt during the pre-dive to confirm that diluent
will be automatically changed to air.
Procedure
After inserting a Recreational 40m or yellow Deco 40m battery into a SE7EN that was previ-
ously configured for non-air diluent (e.g., trimix), the pre-dive routine will display tests 51 and
52 as described above for the user to confirm and acknowledge that the diluent will be air (0%
Helium, and 21% oxygen). If these tests are completed successfully, the unit will automatically
switch the diluent composition to air. If the Recreational 40m battery or Deco 40m battery was
inserted by mistake, the diver should NOT confirm these tests. Instead, the test should be
allowed to time out (two minutes) after which the rig will power-down, and then the correct
(Deco 48m/60m) battery can be inserted. In this case, the original non-air diluent will be retained.
On a unit with the blue 48m, 60m or 100m Trimix battery installed, the diver will be prompted to confirm
the helium fraction (pre-dive test 51) and O2 fraction (test 52) of the diluent mixture. This test occurs
immediately after the mouthpiece ‘CC’ test (test 50), and will occur only if the SE7EN is configured for
decompression diving, or if the configured diluent is not air (the test is not performed if the rig is not
configured for decompression diving and the diluent is already configured as air).
The M28 will display ‘is DIL Helium fraction nn%’ during test 51 where ‘nn’ is the assumed Helium
fraction. The diver is prompted to confirm YES or NO using the M28 buttons. During test 52 the
procedure is repeated but now the diver is supposed to confirm the Oxygen content in the diluent.
See figures 3-43 and 3-44.
If the helium or oxygen fraction is incorrect, the diver can either:
1. Use the PC Bluetooth link or the M28 to alter the CC gas to any of the predefined gases
through the ‘CC Gas select’ option in the Dive menu. The gas content can be altered while in
test 51 but not after. to change it to the correct value. The new value will appear in the LCD.
2. Let the test timeout (two minutes) at which point the rig will shut down.
