ISCO 4210 - Checking and Regenerating the Desiccant

4210 Flow Meter
Section 5 Maintenance and Service
5-2
It is also important to keep the external connectors clean by
keeping the mating connectors or the protective caps tightly
screwed down. Under severe operating conditions, you can spray
the threads of the connectors with a cleaner/lubricant (such as Jif
manufactured by GC Electronics or WD-40 manufactured by the
WD-40 Company) to prevent corrosion. Be careful not to spray
any of the conductive terminals (pins or jacks) inside the con-
nectors; residue from the sprays could cause intermittent or
failed contacts.
5.1.4 Checking and
Regenerating the
Desiccant
As shown in the picture, the 4210 is equipped with a reusable
desiccating canister attached by a spring steel clamp attached to
the inside of the flow meter's lid. This canister contains silica gel
that attracts moisture trapped inside the flow meter's case when
it is closed. This keeps the inside of the case completely dry
during shipment, storage and use. If you leave the case open, the
desiccant will attract moisture from the surrounding air. Even-
tually, its absorption capacity will be reached, and it will no
longer be able to protect the internal components of the flow
meter.
Inspect the desiccant canister each time the case is opened. The
desiccant canister has a window on its side that looks blue or
black when the desiccant is in dry. As the desiccant adsorbs
moisture, the pebbles in the window will turn pink or pale amber.
When the pebbles turn pink, the desiccant needs to be regen-
erated, or replaced with the spare canister provided in the flow
meter's accessory package.
Remove the canister from the flow meter by pulling out on the
spring clamp that holds it in place. Lift the canister from the
mounting bracket and heat it in a vented oven at 300°F (150°C)
for about three hours, or until the blue color returns. After
cooling, put the canister back in the flow meter; make sure the
window on the side of the canister remains visible.
CAUTION
Desiccant may produce irritating fumes when heated. Leave
the room while the desiccant is being recharged.
Important Guidelines to Follow:
• Always use a vented, circulating forced air, convection
oven in a well-ventilated room.
• DO NOT use a microwave oven to recharge the
desiccant cartridge.
• Always use the recommended temperature. Never heat
the desiccant at higher than recommended tempera-
tures.
• Avoid heating the desiccant longer than necessary.