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recommended to shorten replacement interval if the silica-gel is
completely transparent upon replacement. If it is still yellow-orange, it is
possible to prolong the replacement interval.
Figure 23: Silica-gel container is accessible from the camera back side
Exchanging the silica-gel
C1+ cameras employ the same desiccant container like the larger C2, C3
and C4 cameras as well as the cooled Gx CCD cameras. The whole
container can be unscrewed, so it is possible to exchange silica-gel without
the necessity to remove the camera from the telescope.
Silica-gel is held inside the container with a perforated cap. This cap is also
screwed into the container body, so it is easy to exchange the silica-gel
inside the container after it is worn out or damaged e.g. by too high
temperature etc.
The container itself does not contain any sealing (the sealing remains
attached to the sensor cold chamber inside the camera head), it consists of
aluminum parts only. So, it is possible to heat the whole container to
desired temperature without risking of the temperature-induced sealing
damage.
