51
4.8 Centration of the 12 V 100 W, Hg, Xe lamps*
Lamphousing 107/2 for 12 V 100 W halogen lamp
This lamphousing is permanently set and does
not require centration. However, it is essential
that the lamp is aligned straight in its mount.
Lamphousing 107 L for 12 V 100 W halogen
lamp (68)
2 alternative centration methods:
Method 1:
Centration in the rear focal plane of the objec-
tive
1. Turn a low-power objective into the light path
and, using the BF reflector, focus on a strong-
ly reflecting specimen (e.g. surface mirror)
with the coarse and fine drive. Open the field
and aperture diaphragm (72.1+3).
2. Remove the eyepiece from the right or left
tube and look into the empty eyepiece tube.
3. Slightly reduce the light intensity until the
back objective pupil (back lens surface of the
objective) can be clearly seen.
4. Adjust the lamp collector (68.4) until you see
the structure of the lamp filament. The fila-
ment image is divided into two with a pale
stripe in the middle (69).
Please note that only the central area of the
filament can be seen and that the image is
very low in contrast.
5. Using an Allen key (68.3), adjust the screw for
horizontal adjustment (68.2) until the pale
stripe of the filament image is in the centre of
the pupil.
6. Then adjust the screw for vertical adjustment
(68.3) to align the filament image vertically in
the centre of the pupil.
Fig. 68
Lamphousing 107 L
1
Cover fixing screws,
2
Screw for horizontal adjustment,
3
Screw for vertical adjustment,
4
Collector focusing
Fig. 69
Lamphousing 107/2 and 107 L
Reflection of the lamp filament, (greatly schematized): the reflec-
tion is actually very low in contrast, the pale overlap area is
wider and more blurred. For lamphousing 106 z the reflection is
rotated by 90°.
3
2
1
4
