Leica Builder T User Manual page 168

Check & Adjust
Type Description
i A vertical index error (i) exists, if
the 0° mark of the vertical circle
reading doesn't coincide with
the mechanical vertical axis of
the instrument, also called
standing axis. The vertical index
error (i) is a constant error that
affects all vertical angle read-
ings.
l, t Compensator longitudinal (l) and
transversal (t) index errors
Builder
Diagram
a
a) Mechanical vertical axis of the
instrument, also called standing axis
b) Axis perpendicular to the vertical
axis
c) V = 90° reading
d) Vertical index error
b d
c
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