Hollis Explorer User Manual - page 49
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So, calibration checks, not actual calibrations, should be car-
ried out regularly to ensure the oxygen PO
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sensing system is
performing correctly. Calibrations should be done more spar-
ingly, as it takes time to ensure sensors are exposed to the cor-
rect conditions. Often a bad calibration causes more confusing
problems than small errors due to temperature change. User
error caused by failure to use the appropriate ambient gas (air)
is a big source of sensor errors.
1. Don't mask problems with excessive calibrations.
2. If something seems wrong, check everything. Do not just
execute a calibration to fix the reading. You could be making
matters worse.
3. Keep sensors dry.
4. When doing a calibration, ensure the sensors are exposed to
air by following all on screen handset instructions.
5. Just removing hoses is not enough to get air to the sen-
sors. Either the breathing routine described in the Pre-Dive
sequence must be used or the Sensor Module should be re-
moved from the EXPLORER and sensors allowed to stabilize in
ambient air.
6. If the EXPLORER has had a change in climate or significant
ambient conditions, these are good reasons to check calibra-
tion.
7. The readings from the oxygen sensors change with tempera-
ture. If you are diving in warmer or colder water than normal,
PO
2
readings will vary. Ensure calibrations take place at a tem-
perature as close to diving conditions as possible.
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