Shearwater DiveCAN
®
Petrel
DocRevB
35
Calibration Problems
One sensor displays FAIL after calibration
This could indicate a bad sensor� It has failed because the mV output
was not in range� The sensor could be old or damaged, and should
be inspected� Damage and corrosion to wires or connectors is also a
common problem� Fix the problem and recalibrate before diving�
All sensors display FAIL after calibration
This could be caused by an accidentally unplugged cable or a
damaged cable or connector� Also, accidentally performing the
calibration in air or without a proper oxygen flush could cause this
problem. A failed calibration can only be fixed by performing a
successful calibration�
PPO2 does not show 0.98 after calibration
If the Altitude setting in the Display Setup menu is set to Auto, then the
PPO2 after calibration may not be exactly equal to the F02�
This is because weather causes minor changes in barometric
pressure� For example, say a low-pressure weather system has
reduced the normal (1013mbar) barometric pressure to 990mbar� The
PPO2 in absolute atmospheres is then 0�98 * (990/1013) = 0�96�
The 0�96 PPO2 result is, in this case, correct� At high altitudes, the
difference between FO2 and PPO2 will be even larger� To see the
current pressure, start at the main screen and press the SELECT
button a few times (displays as Pressure mBar NOW)�
If you are at sea level, and want the calibrated PPO2 to exactly match
the FO2, then change the Altitude setting to SeaLvl� Only do this when
actually at sea level, and also be aware that using this SeaLvl setting
is actually introducing error into the PPO2 measurements�
DEPTH TIME STOP TIME
.98 .97
FAIL
O2/HE NDL TTS
CC 21/OO O O
O
DEPTH TIME STOP TIME
FAIL FAIL FAIL
O2/HE NDL TTS
CC 21/OO O O
O
DEPTH TIME STOP TIME
.96 .96 .96
O2/HE NDL TTS
CC 21/OO O O
O
DEPTH TIME STOP TIME
.96 .96 .96
PRESSURE mBar
O
SURF
99O 99O
NOW