Humidifier Calibration - GE Giraffe OmniBed Service Manual

3.5 Humidifier Calibration

IMPORTANT: Be sure to re-calibrate the humidifier whenever either the sensor or the control board is replaced.
IMPORTANT: In order for the water in the calibration bottle (6600-0048-850) to be completely saturated, most
of the salt should not be dissolved. There should be as little standing water above the salt line as possible to
minimize the response time. The salt in the calibration bottle may only be used for a period of one year after its
initial mix with water then the kit should be discarded.
1. Take the cap off the humidity calibration bottle and add one half cap full of sterile distilled water to the
bottle. Shake the bottle to thoroughly mix the salt and water solution. Place the smaller end of the elbow
over the bottle.
2. Slide the elbow over the humidity sensor (mounted on the back wall) until it stops. This creates a 75% RH
environment for the sensor.
3. Hold the override key while powering up to enter the service screen.
4. On the second service screen, select Cal RH. The screen will prompt "Push knob when RH reading is stable."
Wait for 20 minutes or until the RH display stabilizes (does not change by more than 1% in 5 minutes).
5. Depress the control knob to complete the calibration. On software revision 1.3 and higher, you will have
the option to select STABLE, SET TO DEFAULT or EXIT. STABLE initiates calibration. SET TO DEFAULT resets
calibration values back to factory default settings. If you started calibration by mistake (without the
calibration bottle in place, for example) you would select SET TO DEFAULT and then calibrate the unit. If you
have entered the calibration routine by mistake, select EXIT to leave without initiating calibration.
6. If "RH Sensor Calibration Completed" is displayed, the calibration is complete. Depress the knob to exit the
Cal RH routine.
7. If "RH Sensor Calibration Failed Try Again" is displayed, verify your setup and press the knob to try the
calibration again. This message appears if the signal from the RH sensor is outside the values expected
from the sensor at 65-85% RH. If the failure persists it means the readings are out of this range and either
the calibration bottle or the RH sensor may be defective.
© 2001 by Datex-Ohmeda, Inc.. All rights reserved.
Chapter 3: Calibration and Maintenance
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