Petrel Manual v1.2.0 - Shearwater Research

Shearwater Petrel SA & EXTSingle Sensor ModeA single external O2 sensor may be used.To enter this mode, perform the calibration with only the middle sensorconnected.The Petrel will see that only one sensor is connected, andautomatically switch to single sensor mode.Calibration ProblemsOne sensor displays FAIL after calibrationThis could indicate a bad sensor. It has failed because the mV outputwas not in range. The sensor could be old or damaged, and shouldbe inspected. Damage and corrosion to wires or connectors is also acommon problem. Fix the problem and recalibrate before diving.Cal. milliVoltsO 46 O.OO .86 .OOCal. @ FO2= .98CancelCalibrateDEPTH TIME STOP TIMEO.98O2/HE NDL TTSCC 21/OO O ODEPTH TIME STOP TIMEO.98 .97 FAILO2/HE NDL TTSCC 21/OO O OAll sensors display FAIL after calibrationThis could be caused by an accidentally unplugged cable or adamaged cable or connector. Also, accidentally performing thecalibration in air or without a proper oxygen flush could cause thisproblem. A failed calibration can only be fixed by performing asuccessful calibration.DEPTH TIME STOP TIMEOFAIL FAIL FAILO2/HE NDL TTSCC 21/OO O OPPO2 does not show 0.98 after calibrationIf you use a calibration FO2 setting of 0.98 and are at sea level, youprobably expect the calibrated PPO2 to show 0.98. Sometimes youmight correctly get a different value like 0.96 or 1.01.This is because weather causes minor changes in barometricpressure. For example, say a low-pressure weather system hasreduced the normal (1013mbar) barometric pressure to 990mbar. ThePPO2 in absolute atmospheres is then 0.98 * (990/1013) = 0.96.The 0.96 PPO2 result is, in this case, correct. At high altitudes, thedifference between FO2 and PPO2 will be even larger. To see thecurrent pressure, start at the main screen and press the SELECTbutton a few times (displays as Pressure mBar NOW).DEPTH TIME STOP TIMEO.96 .96 .96O2/HE NDL TTSCC 21/OO O ODEPTH TIME STOP TIMEO.96 .96 .96PRESSURE mBarSURF 99O NOW 99O31Revision 1.2.0