14
Fig. 3
7
Centering the Mercury Burner
}Set the main switch to “
I
” (ON) and wait for 5 to 10 minutes until the arc
stabilizes before proceeding to the mercury burner centering.
1. Close the light path by sliding the shutter knob @ to position marked {.
2. Engage the B or IB mirror unit in the light path by rotating the turret.
(If these mirror units are not available, engage another fluorescence mir-
ror unit in the light path. Also note that, when using a U-excitation fluores-
cence mirror unit, be sure to observe the specimen through a UV cut
plate.)
3. Engage the 10X objective in the light path, place the U-CST centering
target on the stage, and adjust the centering of the center of crosslines
on white surface of the U-CST with respect to the center of field of view.
4. Turn the revolving nosepiece to engage the empty position (the objective
cap should be removed) in the light path.
5. Pull out the field iris diaphragm knob ² (to minimize it) and push in the
aperture iris diaphragm knob ³ (to enlarge it).
6. Open the shutter by setting shutter knob @ to position marked \.
7. Project the arc image on the U-CST by turning the collector lens focusing
knob |. (A)
If the arc image is not protected, adjust the burner centering knobs ƒ.
8. ring the arc image on the center of the left (or right) half of the field by
turning the burner centering knobs ƒ. (B)
9. Focus on the mirror arc image by adjusting the mirror focus screw … (Fig
4) on the rear of the lamp housing using the Allen screwdriver. (C)
Overlay the arc image with the mirror arc image by turning the burner
centering knobs ƒ. (D)
}During observation, adjust the collector lens focusing knob | so that the
observed field is uniform.
}Hereafter, the mercury burner centering need not be adjusted until the
next time the mercury burner is replaced.
@
² ³
|
ƒ
A
B
C
D
10.
