To Calibrate The Maxo2 Me Monitor To 20.9% Oxygen; To Calibrate The Maxo2 Me Monitor To 100% Oxygen; Factors Influencing Oxygen Calibration; Operating Instructions - Maxtec MaxO2 ME Instructions For Use Manual

mix and the barometric pressure drops from 1000mbar to 990mbar the reading will drop to:
50% x (990/1000) = 49.5%). Maxtec recommends that you re-calibrate after changing point-
of-use elevation by more than 500 feet (150m).
In addition, calibration is recommended if the user is unsure when the last calibration proce-
dure was performed or if the measurement value displayed is in question.
It is best to calibrate the MaxO2 ME monitor at a pressure and flow similar to your clinical
application.
NOTE: Before beginning calibration the Max-550E sensor must be in thermal equilibrium.
You may also need to be aware of other factors which affect device calibration values. For
more information, refer to "Factors Influencing Calibration and Performance" in this manual.
The main display is capable of reading oxygen in the range of 0-105%. This additional range
beyond physically possible concentration is to allow the user to be able to see if the device is
reading accurately by testing in room air or 100% oxygen.
2.2.2 To Calibrate the MaxO2 ME Monitor to
20.9% Oxygen
1. Ensure the sensor is in room air and has had sufficient time to equilibrate with room
temperature.
2. Using the ON/OFF key , make sure the unit is powered on.
3. Allow the oxygen reading to stabilize. This will normally take about 30 seconds or
more.
4. Press the Unlock key to unlock the keypad. Note the LOW, Smart Alarm, CAL, and
HIGH icons will begin to flash indicating the SET OPERATING MODE.
5. Press the CALIBRATION key
display for approximately 5 seconds and then finish with 20.9%.
6. The unit is now calibrated and in the normal operating mode.
2.2.3 To Calibrate the MaxO2 ME Monitor to
100% Oxygen (recommended)
1. Place the external probe in a stream of medical grade USP or greater than 99% purity
oxygen. Expose the sensor to the calibration gas at a regulated pressure and flow at a
rate of 1-10 liters per minute (2 liters per minute is recommended).
2. Using the ON/OFF key , make sure the unit is in the normal operating mode.
3. Allow the oxygen reading to stabilize. This will normally take about 30 seconds or
more.
4. Press the Unlock key to unlock the keypad. Note the LOW, Smart Alarm, CAL and
HIGH icons will begin to flash indicating the SET OPERATING MODE.
5. Press the CALIBRATION key
display for approximately 5 second and then finish with 100.0%.
6. The unit is now calibrated and in the normal operating mode.
2.2.4 Factors Influencing Oxygen
Calibration
The primary factors influencing oxygen measurement on the MaxO2 ME monitor are tempera-
ture, pressure, and humidity.
Effects of Temperature
The MaxO2 ME monitor will hold calibration and read correctly within +/-3% when in thermal
equilibrium within the operating temperature range. The device accuracy will be better than
+/-3% if operated at the same temperature at which it was calibrated. The device must be
thermally stable when calibrated and allowed to thermally stabilize after experiencing tem-
perature changes before reading is 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.
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on the keypad. The word "CAL" will appear on the
on the keypad. The word "CAL" will appear on the
3. For best results, perform the calibration procedure at a temperature close to the
temperature where analysis will occur.
Pressure Effect
Readings from the MaxO2 ME monitor are proportional to the partial pressure of oxygen. The
partial pressure of Oxygen (PO2) is equal to the percentage of oxygen (%O2) times the abso-
lute pressure (AP) at which the sample environment is measured (PO2=%O2 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 sensor in that back pressure at the sensing point
may change. For these reasons, the following is recommended:
1. Calibrate the MaxO2 ME monitor at the same pressure as the sample gas.
2. If sample gases flow through tubing, use the same apparatus and flow rates when
calibrating as when measuring.
Humidity Effect
The MaxO2 ME monitor can be used in applications where the relative humidity of the sample
gas ranges from 0 to 95%, non-condensing. However, it should be noted that water vapor
exerts its own pressure in the same manner as oxygen does in a sample gas stream.
For example, if the monitor is calibrated in dry gas and then the gas is humidified, the monitor
will correctly display a reading which is slightly lower than previously displayed. This is due to
the dilution of oxygen in the sample gas by water vapor.
This fact is important to note in systems where there exist both "wet" and "dry" gas streams
such as in a ventilator circuit. If the monitor is measuring oxygen on the "dry side" of the ven-
tilator, it will correctly indicate an oxygen concentration slightly greater than actually found in
the "wet side" (delivered to the patient). The water vapor has diluted the gas stream.
Additionally, gas streams of high humidity may tend to condense on the sensor. Condensation
on the sensor may eventually affect performance. For this reason, it is recommended that the
sensor be mounted in a vertical position, facing downward to prevent condensate from flow-
ing onto the sensing surface.
3.0 OPERATING INSTRUCTIONS
3.1 Alarm Setting Procedure
3.1.1 Low Alarm Setting
To adjust the low alarm setting:
1. Press the Unlock key to unlock the keypad. Note the LOW, Smart Alarm, CAL and
HIGH icons will begin to flash indicating the SET OPERATING MODE.
2. Press the DOWN (LOW ALARM) key
NOTE: The Low Alarm digits begin to flash indicating the Low Alarm manual setting.
3. Use the UP and DOWN
Pressing the arrow keys changes the value in 1% increments. If the keys are held down
for more than 1 second the display will scroll at a rate of 1% per second.
NOTE: If 30 seconds elapse between key actuations, the system will store the latest low alarm
value and will revert to normal operation. If this occurs inadvertently, simply repeat the alarm
setting procedure.
There is a special condition that allows the low oxygen alarm to be set below 18%. To access
this condition press the DOWN arrow
displays 18%. The alarm setting can now be adjusted to 17, 16, or 15%. A bar will blink above the
setting to provide further indication that the alarm has been set to this special <18% condition.
7
on the keypad.
keys to set the low alarm to the desired value.
key for three seconds while the low alarm reading
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