866.4.Maxtec www.maxtecinc.com
5
continues to occur, contact the service department of the
distributor from which the unit was purchased, or you may call
Maxtec's Customer Service Department directly.
2.2.3 Automatic Calibration to Room Air
The MAXO
2
®
analyzer can quickly be calibrated to room air (20.9%)
using a quick-key shortcut command. This function saves time by
setting the calibration value to 20.9% without scrolling the display. To
use this function:
1. Introduce room air to the sensor at a rate of 1-5 liters per minute
(2 liters per minute is recommended) and allow the reading to
stabilize.
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
®
analyzer are
temperature, pressure, and humidity.
Effects of Temperature
The MAXO
2
®
analyzer 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 readings are accurate. For these reasons, the
following is recommended:
1. Allow adequate time for the sensor to equilibrate to a new ambient
temperature.
2. For best results, perform the calibration procedure at a
temperature close to the temperature where analysis will occur.
Pressure Effect
Readings from the MAXO
2
®
analyzer are proportional to the partial
pressure of oxygen. The partial pressure of Oxygen (PO
2
) is equal to
the percentage of oxygen (%O
2
) times the absolute pressure (AP) at
which the sample enviroment is measured. (PO
2
=%O
2
x AP). Thus
the readings are proportional to the concentration if the pressure is
held constant. Flow rate of sample gas can affect pressure at the
Summary of Contents for MaxO2 OM-25A
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