4-1

Teledyne Analytical Instruments
Model OT-2 System Maintenance 4Maintenance

4.1 Routine Maintenance

Aside from normal cleaning and checking for leaks at the gas
connections, routine maintenance includes servicing the filter, the
scrubber, installing replacement Micro-Fuel cells and recalibration.
For recalibration, see section 3.3

Calibration

.

4.2 Cell Replacement

The Micro-Fuel Cell is a sealed electrochemical transducer
with no electrolyte to change or electrodes to clean. When the
cell reaches the end of its useful life, it is replaced. The spent fuel
cell should be discarded according to local regulations.
The characteristics of the Micro-Fuel Cell are similar to those
of a mercury battery in that both provide an almost constant
output (when the sensor is exposed to a constant level of oxygen)
throughout their useful life, and then fall off sharply towards zero at
the end. Cell failure, in the Model OT-2 System, will probably be
indicated by the inability to properly span calibrate the transmitter,
or excessively long response time to changes in oxygen concen-
tration.
To ensure availability, TAI recommends that a spare cell be
purchased shortly after the instrument is placed in service, and
each time the cell is replaced.
The spare cell should be carefully stored in a cool, and near
constant temperature, area if possible.
NOTE: Do not disturb the integrity of the cell package until the
cell is to actually be used. If the cell package is punctured
and has been exposed to atmospheric air over an ex-
tended period, the sensor may not function properly.
Power must be removed from the OT-2 prior to removing or
installing the sensor.