Oxygen Equipment User Manual

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CAUTION: The Maxtec MAX-250E oxygen sensor is a sealed
device containing a mild acid electrolyte, lead (Pb), and lead
acetate. Lead and lead acetate are hazardous waste
constituents and should be disposed of properly, or
returned to Maxtec for proper disposal or recovery.
CAUTION: Do not use ethylene oxide for sterilization. Do
not immerse the sensor in any cleaning solution, autoclave
or expose the sensor to high temperatures.
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1.3 MAX-250E Oxygen Sensor
MAX-250E oxygen sensors offer quick response, stability and extra life on
the order of 900,000 percent hours.
The MAX-250E is a galvanic, partial pressure sensor that is specific to
oxygen. It consists of two electrodes (a cathode and an anode), a teflon
membrane and an electrolyte. Oxygen diffuses through the teflon
membrane and immediately reacts electrochemically at a gold cathode.
Concurrently, oxidation occurs electrochemically at a 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.
CAUTION: Dropping or severely jarring the sensor after
calibration may shift the calibration point enough to require
recalibration.
CAUTION: The flow diverter for the sensor is for use with
flowing gases only. Do not use the diverter when
performing static sampling, such as in incubators, oxygen
tents, oxygen hoods, etc.
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