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Revision NEW
APECS™ 2.7
15 of 19
Date: 10 July 2008
APECS
™ OPERATIONAL
INSTRUCTIONS (v. 2.7)
Loop Flush High Point Calibration
1. Perform all Pre-dive check procedures up to the step “Complete
calibration if necessary”. To complete calibration, all performance checks
prior to this need to be completed. Insure that negative pressure check
step was good and apply another vacuum to the loop sucking all the
ambient air out of the loop. Next, close the vent valve on the exhaust
counterlung and fill the loop with 100% Oxygen until the vent valve vents
gas. Let set for 10 seconds.
2. Vacuum the loop again and fill again until the vent valve vents and repeat
above.
3. Open the vent valve all the way and tightly pinch the exhaust breathing
hose to isolate the exhaust counterlung from the oxygen bypass on the
inhalation counterlung.
4. Push the oxygen manual bypass for 3 seconds; this will blow 100%
oxygen over the sensors without increasing the loop pressure giving a
possible higher PO2 reading.
5. Repeat 4 above.
6. Repeat 4 again.
7.
You now have a purged loop with nearly 100% Oxygen. You will observe
the sensor millivolt output in both displays and the normal output is in the
zone of 35 to 60 millivolts.
Note: The lower the sensor mv output at both points of calibration the
lower the sensor mv reading. Beware that the sensor is reaching its end of
useful life.
8. Push the yes button on the displays and you have finished the two point
calibration.
