Max-250 Oxygen Sensor; Operating Instructions; Getting Started; Protect Tape - Maxtec MaxO2 Plus Operating Manual & Instructions For Use

1.5 MAX-250 Oxygen Sensor

The MAX-250+ oxygen sensor offers stability and extra life. The MAX-250+ is
a galvanic, partial pressure sensor that is specific to oxygen. Itconsists of two
electrodes (a cathode and an anode), a teflon membrane and an electrolyte.
Oxygen diffuses through the teflon membrane and immediately reacts at a gold
cathode. Concurrently, oxidation occurs electrochemically at the lead anode,
generating an electrical current and providing a voltage output. Electrodes are
immersed in a unique gelled weak acid electrolyte which is responsible for
the sensors long life and motion insensitive characteristic. Since the sensor
is specific to oxygen, the current generated is proportional to the amount of
oxygen present in the sample gas. When no oxygen is present, there is no
electrochemical reaction and therefore, negligible current is produced. In this
sense, the sensor is self-zeroing.

2.0 OPERATING INSTRUCTIONS

2.1 Getting Started

2.1.1 Protect Tape

Prior to turning on the unit, a protective film covering the threaded sensor face
must be removed. After removing the film, wait approximately 20 minutes for
the sensor to reach equilibrium.

2.1.2 Automatic Calibration

After the unit is turned on it will automatically calibrate to room air. The
display should be stable and reading 20.9%.
CAUTION: The device will assume a percent oxygen concentration when calibrating.
Be sure to apply 100% oxygen, or ambient air concentration to the device during
calibration or the device will not calibrate correctly.
To check the oxygen concentration of a sample gas:
(after the unit has been calibrated)
1. Connect the Tygon tubing to the bottom of the
analyzer by threading the barbed adapter onto
the oxygen sensor. (FIGURE 2, B)
2. Attach the other end of the sample hose to the
sample gas source and initiate flow of the sample
to the unit at a rate of 1-10 liters per minute (2
liters per minute is recommended).
3. Using the "ON/OFF"
unit is in the power "ON" mode.
4. Allow the oxygen reading to stabilize. This will
normally take about 30 seconds or more.
key, make sure the
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A B
FIGURE 2
3