User manual

Poseidon MKVI User Manual
Chapter 3
Page 54
Oxygen sensor condence
One of the most sophisticated features of the
Poseidon MKVI is the automatic oxygen sensor
validation system, which monitors the reliability
of the oxygen sensors throughout the dive.
Through a series of algorithms, the system
assigns a condence rating to current oxygen
sensor readings, based on several factors includ-
ing primary sensor validation, dynamic response
of sensors, and a comparison between primary
and secondary sensor values. If, for some
reason, the system loses condence in the
oxygen sensors, then every few seconds an error
will be displayed momentarily on the Primary
Display where the PO
2
value is normally dis-
played – in a manner similar to how the PO
2
Setpoint is displayed. If there is no condence in
the oxygen sensors, then “C0” is displayed.
Other levels of condence based on various
factors include “C1”, “C2”, and “C3”. The last of
these (“C3”) is normal, and means the system
has high condence in the sensors. The other
levels (“C0”, “C1” & “C2”) generate errors, and
will trigger appropriate alarms.
Figure 3-16. Oxygen sensor condence alerts: C0, C1, C2.
Mouthpiece position
• “nc” with “n” in the lower half, and “c” in the upper half (mouthpiece is not fully in either
position), or “un” with “u” in the upper half, and “n” in the lower half (mouthpiece position
is unknown).
The difference between “nc” (“no circuit”) and “un” (“unknown”) depends on whether the
mouthpiece is reporting that neither closed-circuit nor open-circuit is currently established (“no
circuit”), or whether the mouthpiece is not reporting any position information at all (“unknown”).
In the former case, the problem is likely due to the mouthpiece switch being in the wrong
position, one or both of the magnets inside the mouthpiece being damaged or corrupted, or a
problem with the magnet sensors in the HUD. The latter case would arise if the HUD was
unable to communicate reliably with the Display. In any case, if the displayed value of the
mouthpiece position is not what it should be, rst check the actual position of the mouthpiece,
make sure it is rmly and completely in one position or the other, and attempt to wiggle the
HUD slightly.
Fig ur e 3 -17. Closed Circuit mode.
Figure 3-18. Open Circuit mode.
The area where the PO
2
is normally displayed serves one additional function: to communicate
the current position of the Mouthpiece. As with the PO
2
Setpoint and Oxygen Sensor Con-
dence warnings, this information is displayed briey every few seconds. There are four possible
values, which are:
• “cc” in the upper half of the PO
2
display area (mouthpiece is in the Closed Circuit position)
• “oc” in the lower half (mouthpiece is in the Open-Circuit position)
Figure 3-19. No Circuit mode.
Figure 3-20. Mouthpiece position Unknown.