52
Method 2:
Centration in the plane of the specimen stage
1. Put a piece of paper or non-shiny piece of
Leica packaging on the specimen stage and
roughly focus the surface with a low-magnifi-
cation objective.
2. Set the field and aperture diaphragms at the
middle position.
3. Make a dot or cross on the centration area
with a felt or ball point pen and slide it into the
centre of the spot of light. Fix with the speci-
men clip if necessary.
4. Screw out the objective or turn an empty
nosepiece position into the light path.
5. Using the centring screws, slide the image of
the filament into the middle of the centration
area marked with a dot or cross, as described
in Method 1.
Lamphousing 106Z L with halogen lamp, Xe and
Hg lamps
(switch gas discharge lamps on and off at sepa-
rate power units)
For lamphousing 106Z the direct lamp image and
the reflection of the reflector are focused sepa-
rately and aligned to each other.
Either of the above methods can be used for im-
aging the lamp filament or arc.
Centration of 12 V 100 W halogen lamp
Move the reflection of the filament to the side or
entirely out of the light path by adjusting the cen-
tring screws on the back of the lamphousing
(70.4, 71). Focus the direct image of the filament
with the collector adjustment (70.6)
Then, using the centring buttons, adjust the
image of the filament until the centration area or
rear focal plane of the objective is half filled (71.b)
Then focus the reflection of the filament with the
centring buttons for the reflector adjustment and
align symmetrically to the direct image (72c).
Fig. 70
Lamphousing 106Z with Hg 100W lamp
1
Lamp adjustment, vertical,
2
Reflector adjustment,
3
Focu-
sing of the reflector image,
4
Reflector adjustment, horizontal,
5
Lamp adjustment, horizontal,
6
Collector focusing
4
3
2
6
1
5
n.b.:
Risk of glare with gas discharge lamps. Use
neutral density filter (see p. 56).
