MaxTech MAXO2 OM-25ME - Manual (Page 17)

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To use this function:
1) Place the external probe in room air.
2) Press the LOCK\UNLOCK key to unlock the keypad.
3) Press and hold down the CALIBRATE key. When the "%" sign
starts to flash, press the
↓ arrow key to set the calibration value to
20.9%.
4) Release both the CALIBRATE key and the ↓ key.
The unit will automatically enter the “LOCKED” condition and return to
normal operation.
2.2.4 Factors Influencing Calibration
The primary factors influencing the MAXO
2
Monitor are temperature,
pressure, and humidity.
Effects of Temperature
The MAXO
2
Monitor will hold calibration and read correctly within ±3%
when in thermal equilibrium within the operating temperature range. The
device must be thermally stable when calibrated and allowed to thermally
stabilize after experiencing temperature changes before reading are
accurate. For these reasons, the following is recommended:
1) Allow adequate time for the sensor to equilibrate to a new ambient
temperature.
2) When used in a breathing circuit, place the sensor upstream of the
heater.
3) For best results, perform the calibration procedure at a temperature
close to the temperature where analysis will occur.
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