Datex-Ohmeda Aestiva 7900 SmartVent, Service Manual

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4/Tests and Troubleshooting
4-24 1503-0151-000 5/26/0
4.5. Calibrations
Calibrate O
2
Sensor
See operation and maintenance manual.
The software calibrates the O2 sensor at a selected altitude, see "Select Altitude"
menu. Set the appropriate altitude for the machine location. The software in the
ventilator calibrates the O2 sensor by reading the A/D for the O2 sensor when the
O2 sensor is exposed to room air (21% O2). If this A/D value is not within the tol-
erance the calibration fails. If the calibration passes, the A/D value at which the O2
sensor was calibrated is stored in the EEPROM.
The sensor must be calibrated at 21% O2 before calibration at 100% O2.
Remarks
See operation and maintenance manual.
Remove the O2 sensor from the 15 mm adapter, ensure that the sensor is in an
upright position with the cable connector at the top, and expose it to room air for
approximately 3 minutes. The displayed reading should be 21%
±
2% to pass the
calibration requirements. Place the sensor that passed the 21% test in the breath-
ing system and expose it to 100% O2 for 3 minutes.
If the sensor passes, the A/D value at which it passed is stored in the EEPROM. If
it displays readings higher or lower than required to pass, the sensor is bad. Re-
place it.