Polaroid CCD Camera - Manual (Page 43)

Section 6 - Accessories for your CCD Camera
Page 39
6. Accessories for your CCD Camera
This section briefly describes the different accessories available for your CCD camera.
6.1. Cooling Booster
The cooling booster, which is included with the ST-9E and ST-10E, is an option for the
ST-7E, ST-8E and ST-1001E. It is a small module that gets installed inside the back
compartment of the camera. This section tells you how to best use the Cooling Booster.
Caution: Do not connect the power to the cooling booster unless the main
power to the camera has already been connected and the fan is running. The
fan is needed to keep the booster's heat sink cool.
The cooling booster can be used either without the flowing water or with it. We do not
recommend using water cooling in the field due to the extra equipment necessary such as
water reservoir, pump, hoses and additional power required for the pump. For users who
have fixed sites, or small observatories, the extra equipment required is easier to manage. The
major problem one must deal with is routing the water tubes off the mount to minimize
perturbations to the mount during tracking. In general, try to route tubes (and wires) over the
mount, rather than just let the tubes dangle from the end of a long tube. Water-cooling is
probably not necessary for most users when the air temperature is below 10 degrees C (50
degrees F), since the dark current is fairly low already. Think of it as a summertime accessory!
We do not recommend use of water cooling below freezing temperatures, where antifreeze
must be added to the water. It is simply not necessary then. There is no problem with using
the cooling booster with only air cooling in the winter, though.
Without flowing water the cooling improvement is about 6 degrees C. With it the
cooling improvement is about 15 degrees C. If you plan to use it without the water then you
should disconnect the hoses from the camera and shake out the water trapped in the heat sink.
Disconnecting the hoses will reduce the potential perturbation to your telescope mount.
To operate the cooling booster without water cooling, mount the camera to the
telescope as before and simply plug the auxiliary 12 volt supply jack into the connection on the
camera back plate. Turn on the TE cooling to 100% by giving it a target temperature of –50
degrees. After 10 minutes examine the camera temperature, and reset the set point to 3
degrees C above the current temperature. This 3 degree temperature margin will enable the
ST-7E/8E/9E to regulate the temperature accurately.
To operate the camera with water cooling, the procedure is the same except that the
water flow must be established before mounting the camera to the telescope, since the water
pumps have limited pressure capability. To do this, put the camera at the same level as the
water reservoir. Connect all the hoses, and make sure the water return goes back into the
reservoir. Push the ¼ inch internal diameter (ID) hoses onto the nipples on the back of the
camera so they seal. Attach one hose to the nipple onto the reducing connector that adapts the
¼ inch ID hose to the ½ inch diameter hose from the pump.
Turn on the pump, and let the flow establish itself through the hoses. Next, mount the
camera to the telescope. If you always keep the return hose outlet near the reservoir level the
pump will have no problem raising the water 2 meters (6 feet) off the floor. The limited
pressure capacity of the pump is only a problem when you let the water fall back into the