CMP6, CMP10, CMP11, and CMP21 Pyranometers
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FIGURE 8-1. Reading is reduced if dome is not dry or clean
8.1.1 Changing the Desiccant
The CMP10 has an internal drying cartridge that will last for at least ten years
if the housing is not opened. This significantly minimizes maintenance.
The drying cartridge of the CMP6, CMP11, and CMP21 uses desiccant that
needs to be periodically replaced. The silica gel desiccant granules in the
drying cartridge should be orange and opaque. Replace the desiccant granules
when they become translucent (normally after several months). Refill packs of
desiccant are shipped with the pyranometer and can be purchased from
Campbell Scientific. The drying cartridge uses the content of one refill pack.
shows the replacement process.
When changing the desiccant, ensure that:
•
Surfaces touching the rubber O-ring are clean. Dirt, in combination with
water, can cause corrosion, harming it.
•
Rubber O-ring is coated with silicon grease or petroleum jelly. The grease
coating improves the O-ring seal.
•
Drying cartridge is tightly threaded into the pyranometer body.
FIGURE 8-2. Changing the desiccant
