QHYCCD QHY9 - Manual (Page 9)

6) How to avoid moisture in high humidity
Factory default, the QHY9 only has only one optical window (The glass sealing the CCD
chamber).
The QHY9 has an excellent 2 stage TEC which will obtain -50 deg C below ambient. Although
the CCD sensor is located in an airproof chamber, in a high humidity environments where
RH>65%, the front side of the CCD sealing chamber glass may attract moisture. Although
unavoidable due to nature, it can be prevented by:
Method 1: Reducing the TEC power, and avoiding the dew point.
Method 2: Use of dual optical windows by fitting a second optical window (see Section 2, sub
2), to the CCD camera. This to make the whole ccd camera contain its own air and avoid external
cooler air from dewing on the glass. The use of the Air sockets at the same time will help where
humidity is very high.
Note: Use of extra glass will cause a slight loss in optical transmission and may cause reflections
on bright objects, e.g. Stars.
We recommend storing the camera in sealed case, (See section 2 sub 10). The air sealed case with
the electrically heated silicon gel helps to keep the camera dry.
For remote stand alone installations, or when the camera is always fixed to the telescope and the
camera can’t be placed into an airproof case, the air socket can be used to connect a dry air recycle
system to maintain a dry and moisture free camera.
Note: Fast dry method.
A small bag of silicon gel can be put between the two PCB board of the QHY9 camera to achieve
fast dry. Since this method need open the camera case and upper PCB board. This is only used for
urgent conditions.
7) Connection with QHY Filter wheel
The QHY9 has a built in filter wheel control port for the QHY filter wheel.
Connection to the filter wheel is as follows.
Firstly, determine how you want to mount the filter wheel and camera together by using the
adapters as mentioned in accessories in section 2.
Connect QHY filter wheel to the telescope with the supplied M54 to 2” adapter.
Connect the QHY9 filter wheel control port to the filter wheel signal input with the supplied filter
wheel cable (See section 2).