Teledyne 730 Bubbler - Manual (Page 27)

4-1
730 Bubbler Module
Section 4 Maintenance
The 730 Bubbler Module has no user serviceable parts. It is com-
pletely sealed to protect the internal components. If you think
the module requires repair, contact Teledyne Isco’s Customer
Service Department.
4.1 Desiccant
Reactivation
A cartridge on the side of the module dries the air inside the
module and probe reference line. It contains a silica gel desiccant
with a color indicator that changes from blue to pink, or yellow to
green, when saturated. Pink or green desiccant cannot remove
moisture and must be replaced or reactivated.
A saturated desiccator will let moisture into the bubbler system,
which can cause several undesireable effects, including:
· The moisture may block internal tubing and cause
reading errors.
· The air in many installations contains fumes that
will form acids in the presence of moisture. These
acids may corrode internal components.
· At temperatures near or below freezing, there could
be permanent damage if ice forms inside the air
pump.
To reactivate the desiccant, pour the desiccant out of the car-
tridge into a heat-resistant container. Never heat the plastic car-
tridge; it will melt. Heat the silica gel in a vented convection oven
at 212° to 350° F (100° to 175° C) for two to three hours, or until
the blue or yellow color returns. Allow the desiccant to cool and
then refill the cartridge.
CAUTION
Desiccant may produce irritating fumes when heated. Observe
the following precautions:
• Use a vented oven in a well-ventilated room.
• Do not remain in the room while the regeneration is taking
place.
• Use the recommended temperature. Avoid heating the desic-
cant at higher than recommended temperatures.
The desiccant’s ability to remove moisture may lessen with each
saturation/reactivation cycle, resulting in a need for more fre-
quent service. After several cycles, the desiccant may no longer
be effective as it saturates too quickly. At this point, replace the
desiccant.