Teledyne 3110 – Portable Trace/Percent Oxygen Analyzer, unapproved version - Manual (Page 45)

Portable Trace Oxygen Analyzer Maintenance
Teledyne Analytical Instruments 45
Effect of CO2 on B-2 Cell Life
1. This curve assumes continuous exposure.
2. Intermittent exposure will extend life. In
general, the CO
2
effect is cumulative and
the average CO
2
concentration should be
used to find the predicted cell life.
3. Cells can be used to make spot check
measurements of O
2
in the presence of
high concentrations of CO
2
(up to 50%
and more). Any sample containing CO
2
should be purged as soon as a constant
reading is obtained.
4. Abnormally slow response and recovery
is characteristic of cells used as indicated
in notes 1, 2, and 3 above.
5. The reduction in cell life is primarily due
to a drop in output. Cell life will reduce
to a point where the instrument can no
longer be spanned. Instruments using B-2
cells in CO
2
atmospheres should be
spanned at intervals of 10-20% of the
predicted cell life.
6. The CO
2
effect on B-2 cells is
independent of the O
2
level. Usage in
CO
2
contributes significantly to cell life
reduction and thus affects cell warranty.
Figure 4-2: Effects of CO2 on B-2 Cell Life