4-1
Teledyne Analytical Instruments
Percent Oxygen Transmitter Maintenance 4
Maintenance
4.1 Routine Maintenance
Aside from normal cleaning and checking for leaks at the gas connec-
tions, routine maintenance is limited to installing replacement Micro-Fuel
cells and recalibration. For recalibration, see section 3.2 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 throughout
their useful life, and then fall off sharply towards zero at the end. If the
process being analyzed has a low oxygen concentration, cell failure will
probably be indicated by the inability to properly span calibrate the trans-
mitter, or excessively long response time to changes in oxygen concentra-
tion.
To avoid downtime, TBE/AI recommends that a spare cell be pur-
chased shortly after the instrument is placed in service, and each time the
cell is replaced.
The spare cell should be carefully stored in an area that is not subject
to large variations in ambient temperature (75°F nominal), and in such a
way as to eliminate the possibility of incurring damage.
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 air is permit-
ted to enter, the useful life of the cell will be adversely affected.
