Leica DM IRB manual Alternative centration methods, Method Centration with a centring aid

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

(Fig. 68)

3 alternative centration methods:

Method 1:

Centration with a centring aid

On the right side of the microscope there is an adjustment window showing an image of the light source. The reflector for lamp adjustment is inserted in the filter turret instead of a filter cube and turned into the light path.

Centre the lamp as described for method 2 while watching the light source in the adjustment window.

Method 2:

Centration in the rear focal plane of the objective

1.Turn a low-power objective into the light path and, using the BF reflector, focus on a strongly reflecting specimen (e. g. surface mirror) with the coarse and fine drive. Open the field and aperture diaphragm (72.1 + 72.3).

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 filament image is divided into two with a pale stripe in the middle (Fig. 69).

Please note that only the central area of the filament can be seen and that the image is very low in contrast.

Fig.Ê 68ÊLamphousingÊ 107 LÊ

1 Cover fixing screws, 2 Screw for horizontal adjustment,

3 Screw for vertical adjustment, 4 Collector focusing

4

3

1 2

Fig.Ê 69ÊLamphousingÊ 107/2 and 107 L

Reflection of the lamp filament (greatly schematized): the reflection 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°.

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