Handbook for the TRIUS PRO 694 Issue 19th April 2019
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3) Generally speaking, it is possible to unscrew the ring by inserting the tip of a small
screwdriver into one of the notches and pushing it round. Clearly, you need to be
careful that the screwdriver does not slip and scratch the window! Alternatively, you
can make a simple tool by cutting a rectangle of thin metal, so that it sits safely
inside both notches and cannot fall out. A piece of 0.5mm steel about 42mm wide,
will do the job.
4) Once the ring is out, tip the camera onto a clean cloth, so that the silica window
falls out of the barrel.
5) You can now closely examine the CCD faceplate under the spotlight using the
watchmaker's glass, when any dust motes will show clearly. If there is only an odd
particle or two and the CCD is otherwise clean, carefully brush away the dust with a
corner of your lens cloth or a clean soft brush. A smeared or very dusty CCD will
need a few drops of alcohol or acetone to clean thoroughly and you may have to
make several attempts before the surface is free of contamination. One gentle wipe
from one end to the other, with no return stroke, will be found to be the most
effective action. DO NOT rub vigorously and be very careful to avoid scratching the
window. Finish off by giving the CCD a short blast from an air cannon.
6) Before re-assembly, make certain that the inside surface of the front window is
also clean, and then carefully replace the window and retaining ring and screw it into
place. Tighten gently, so that the window is firmly against the nitrile sealing ring.
Dealing with condensation:
The
TRIUS-PRO is designed to avoid condensation by minimising the volume of gas
trapped within the CCD cavity and by preventing moisture ingress. This normally
works very well, but storage of the camera in a humid location can lead to the
trapped argon becoming moist by diffusion through the optical window mounting
thread etc. and can eventually result in condensation on the CCD window. If this
becomes a problem, try storing the camera in a warm, dry place, or in a plastic lunch
box containing a sachet of silica gel desiccant. If this is not effective, it is possible to
flush the CCD chamber with dry argon from a small welding gas cylinder. Such argon
gas cylinders, valves and suitable plastic tubing, are readily available from many car
spares suppliers, such as Halfords, in the UK.Two ports are provided in the sides of
the CCD cavity and these may be accessed by unscrewing the rear plate of the
camera and then sliding off the main barrel.
