Special Precautions Summary

1. Screws must not be overtightened, especially where aluminium thread, are involved.
2. Optical surfaces, particularly grating surfaces, must not be touched or contacted.
3. OBSOLETE, uncorrected The exposure ,meter darkslide must be closed before removing the case lid. As an added precaution the EHT should be switched off.
4. OBSOLETE, uncorrected The shutter should be swung away from the slit by holding the body of the mechanism not the shutter blade.
5. When adjusting the camera mirror focus with the micrometer, ensure that the clamp nut is released. For highest stability this nut should be tightened once best focus has been determined.
6. The grating rotation clamp must be released before the rotation knob is adjusted.
7. There is a possible fouling of the telescope pier by the collimator tube at declinations greater than +70 degrees when operating below the pole.
8. The grating should be protected by a cover during all operations within the casing.
9. Grating angles outside the range +60to -30 should not be set to avoid mechanical fouling between casing and grating.
10. NEEDS TO BE UPDATED When not in use, the field flattener should be protected by either the plateholder or the dummy cover.
11. When removing a corrector unit lift each clamp finger and swing to the side of the cell and not to the rear where there is a danger of contact with the rear optical surface.