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Turn the change-over knob anticlockwise to its stop until the white line is vertical,
open and turn the illumination mirrors towards the light so that the field of view of
reading microscope is evenly illuminated. The vertical circle is read in exactly the
same way as the horizontal circle.
The vertical angle a and the index error i are calculated from:
a = (R – L – 180°)/2
i = (R + L – 360°)/2
R: Reading at face right L: Reading at face left
5. Stadia Survey
The retical plate has a set of stadia hairs with multiplication factor of 100. When
used with a rod, the distance D from station to target can be decided as follows:
D = KL + C = 100L
