Portable Trace Oxygen Analyzer
Maintenance
Teledyne Analytical Instruments
31
Effect of CO2 on B-2CXL 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-2CXL Cell Life