Instrument Errors; Line-Of-Sight Error (Hz-Collimation); V-Index (Vertical Index Error) - Leica T105 User Manual

Instrument errors

The instruments are adjusted in the
factory prior to shipping.
Index-errors and line-of-sight errors
can change with time and
temperature.
These errors should be
determined before the
instrument is used for the first
time, before precision
surveys, after long periods of
transport, before and after
long periods of work, and if
the temperature changes by
more than 10°C (18°F).
T105/T110-1.3.0en

Line-of-sight error (Hz-collimation)

The line-of-sight error or collimation
error (C) is the deviation from the
perpendicular between the tilting axis
and the line of sight.
The effect of the line-of-sight error to
the Hz-angle increases with the
vertical angle.
For horizontal aimings the error of Hz
equals the line-of-sight error.
27

V-Index (Vertical index error)

C
The vertical circle should read
exactly 90° (100 gon) when the line
of sight is horizontal. Any deviation
from this figure is termed vertical
index error (i).
8
i
12
Simple measurements