CST/BERGER SAL20N Manual De Instrucciones página 5

Focusing the instrument
1. Focus the cross hairs (Fig. 3) by pointing the telescope towards a bright
background or holding a white sheet of paper in front of the objective
lens, then turning the eyepiece until the cross hairs are sharp and
black.
2. Focus the telescope by locating a target, such as a leveling rod, using
the optical peep sight. Looking through the eyepiece, use the focusing
knob to bring the target into sharp focus. Center the vertical hair within
the target using the horizontal drive knobs on either side of the instru-
ment.
Reading measurements using a leveling rod
Height reading
Read the rod where it is intersected by the horizontal hair. For example, the
height reading in Fig. 4 (Fig. 4/a) is 2.0 ft (1,195 m).
Distance measurement
Read the rod where it is intersected by the upper and lower stadia hairs; in
Fig. 4 (Fig. 4/a) these readings are at 1.9 ft and 2.1 ft (1,352 m and 1,038 m).
The stadia ratio is 1:100; therefore, the distance from the instrument to the
rod is: (2.1 - 1.9) x 100 = 20 feet - Fig. 4/a (1,352 – 1,038) x 100 = 31,41 m.
Angle measurement
As shown in Fig. 5, sight point A and rotate the horizontal circle until the ref-
erence mark is on "0". Rotate the level and sight point B; the reference mark
will indicate the angle between A and B.
PAL/SALN AutoLevel • 5