User manual

Poseidon MKVI User Manual
Chapter 1
Page 8
IMPORTANT:
If a user removes the battery from the rig they were diving and
then uses that battery in a different Poseidon MKVI unit for
subsequent dives, the decompression data in the rebreather
system will differ from those contained in the battery. To ensure
that a safe decompression situation will always exist, the
backpack computer will take the most conservative tissue-
tension data for each of the nine separate compartments of
the decompression engine from the two sets of values, and use
those to construct a new, worst-case tissue model to be used
on all subsequent dives. This will result in a decompression
penalty (and therefore reduced repetitive no-decompression dive
times) for the user who may have had a lower decompression
exposure before swapping batteries. Conversely, a user with a
known higher decompression debt transferring their battery to a
Poseidon MKVI with a known lower decompression debt will see
little difference in how the rig tracks decompression (except see
Warning message below).
DANGER:
If a user swaps batteries with another Poseidon MKVI unit than the
one they were diving, and if they incurred a decompression debt,
and if the battery computer memory storing the decompression
information is corrupted (e.g. from inadvertant electrostatic
discharge) there is a possibility that the computer system may
only recognize the rebreather system’s stored decompression
data. In that event, and if the previous diver of that rebreather
did not incur as serious a decompression debt, then swapping
batteries could lead to serious injury or death from incorrect
decompression on subsequent dives.
WARNING:
If a user changes batteries with a Poseidon MKVI unit other
than the one they were most recently diving and then turns
on the power of the new Poseidon MKVI with their original
battery installed, the Pre-Dive test routine will FAIL Test 40
(decompression comparison between battery and backpack
computers). This is a warning that there is a difference in the
decompression data stored in the rebreather’s computer and
the battery just inserted. The system will now prompt you for
conrmation while simultaneously scrolling dECO rESEt through
the PO2 eld. The user assumes all responsibility for their own
decompression safety in this event. The rebreather will calculate
decompression based on the most conservative values from
each set of decompression data.
Dive log data
The Poseidon MKVI automatically creates an extensive dive log every time the system is pow-
ered-up. The information stored in this log will be of signicant interest in reconstructing dives
and learning about how the rig and you behave during a dive. A Windows-based MKVI dive log
reviewer are available as a download from Poseidon (www.poseidon.com). In general, the unit
will store approximately 20 hours of dive time; more if the dives were of a simple nature with
uncomplicated proles. Examples of the common types of data you can review are battery
information, dive time and depth. However, the dive log contains much, much more information.
http://www.poseidon.com/support/discovery
O-ring care and maintenance
The Poseidon MKVI is a computer-controlled precision underwater instrument. Its successful
continued operation depends upon preventing water from entering the breathing loop, gas
processor, and electronics systems. To do this, and to keep the rig modular and easy to use
and maintain, there are dozens of o-ring seals. These fall into two design classes: “axial” o-ring
seals and “radial” o-ring seals. Figure 1-10 shows a typical use of a axial o-ring seal, as used