DocRevB
20
Shearwater DiveCAN
®
Petrel
Tissues Bar Graph
The tissues bar graph shows the tissue compartment inert
gas tissue tensions based on the Bühlmann ZHL-16C model�
Note that VPM-B also tracks tensions in the same way�
The fastest tissue compartment is shown on the top, and the
slowest on the bottom� Each bar is the combined sum of the
nitrogen and helium inert gas tensions� Pressure increases
to the right�
The vertical black line shows the inert gas inspired pressure�
The boundary between the green and yellow zones is the
ambient pressure� The boundary between the yellow and red
zone is the ZHL-16C M-Value pressure�
Note that the scale for each tissue compartment above the
green zone is different� The reason the bars are scaled in
this way is so that the tissues tensions can be visualized
in terms of risk (i�e� how close they are as a percentage to
Bühlmann's original super-saturation limits)� Also, this scale
changes with depth, since the M-Value line also changes
with depth�
Battery
The Petrel’s internal battery voltage� Displays in
Yellow
when the battery is low and needs replacement� Displays in
Flashing Red
when the battery is critically low and must be
replaced as soon as possible� Also shows battery type�
External Battery (EXT V)
The voltage of the external battery used to fire the solenoid.
Flashing Red
when the battery is critically low and must be
replaced as soon as possible�
Only sampled when solenoid is fired, so if solenoid has not
yet fired, value is unknown and displays as a
Yellow ?
�
On surface (sat� with air)
After descent
On-gassing
Last deco stop
Some Sample Tissues
Graphs
Ambient pressure
Increasing pressure
M-Value pressure
Inspired inert
gas pressure
16 tissue
compartments
3.99
V
BATTERY
3.7V
LiIon
8.6V
EXT V
Deep stop
EXT V
?
Solenoid
hasn't fired
yet