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zero. Hence, the amount of oxygen diffusing through the membrane
is proportional to the absolute pressure of oxygen outside the
membrane. If the oxygen pressure increases, more oxygen diffuses
through the membrane and more current flows through the sensor. A
lower pressure results in less current.
C A R E , M A I N T E N A N C E A N D
S T O R A G E
This section describes the proper procedures for care, maintenance
and storage of the sensors. The goal is to maximize their lifetime and
minimize down-time associated with improper sensor usage.
GENERAL MAINTENANCE
General Maintenance - O-Rings
The instrument utilizes o-rings as seals to prevent water from entering
the battery compartment and the sensor ports. Following the
recommended procedures will help keep your instrument functioning
properly.
If the o-rings and sealing surfaces are not maintained properly, it is
possible that water can enter the battery compartment and/or sensor
ports of the instrument. If water enters these areas, it can severely
damage the battery terminals or sensor ports causing loss of battery
power, false readings and corrosion to the sensors or battery terminals.
Therefore, when the battery compartment lid is removed, the o-ring
that provides the seal should be carefully inspected for contamination
(e.g. debris, grit, etc.) and cleaned if necessary.
The same inspection should be made of the o-rings associated with
the dissolved oxygen sensor connector when it is removed. If no dirt or
damage to the o-rings is evident, then they should be lightly greased
without removal from their groove. However, if there is any indication
of damage, the o-ring should be replaced with an identical o-ring. At
the time of o-ring replacement, the entire o-ring assembly should be
cleaned.
To remove the o-rings:
Use a small, flat-bladed screwdriver or similar blunt-tipped tool to
remove the o-ring from its groove. Check the o-ring and the groove
for any excess grease or contamination. If contamination is evident,
clean the o-ring and nearby plastic parts with lens cleaning tissue or
