Teledyne 306WA - Analog trace oxygen analyzer - Manual (Page 33)

5-9
TELEDYNE ELECTRONIC TECHNOLOGIES
Analytical Instruments
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5.9.2 Cell Leak 5.9.2 Cell Leak 5.9.2 Cell Leak 5.9.2 Cell Leak 5.9.2 Cell Leak
If there is no rise in oxygen reading when the sample flow is restarted
in step 5.9.1.b, the measuring cell should be checked for leaks. The two
most likely leaks locations are at the two terminal seal O-rings, or at the
large O-ring in the cell block mounting base.
Check that the terminals are screwed tightly into place. Frequently,
when a leak occurs at a terminal connection, a greenish crystalline deposit
will be found inside the cell around the terminal mounting screw. This is
lead carbonate, which is formed by carbon dioxide in the air reacting with
lead ions in the electrolyte.
If the large O-ring at the mounting plate is leaking, the oxygen indica-
tion will begin rising almost immediately after the sample flow is stopped. It
will continue to rise until sample flow is restarted, at which time it will
begin to gradually decrease.