Product Manual

Before starting to work, the instrument has to become acclimatised to the ambient temperature.
Approximately two minutes per °C of temperature difference from storage to working environ-
ment, but at least 15 min, should be taken into account.
6.1.3 Calibrating Line-of-Sight, Vertical Index Error and Compensator
Index Error
The line-of-sight error, or horizontal collimation error 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 horizontal
direction increases with the vertical angle.
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a
b
d
c
a Tilting axis
b Line perpendicular to tilting axis
c Horizontal collimation, or line-of-sight, error
d Line-of-sight
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. This is a constant error that affects all
vertical angle readings.
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b
c
d
a
a Mechanical vertical axis of the instrument,
also called standing axis
b Axis perpendicular to the vertical axis. True
90°
c Vertical angle is reading 90°
d Vertical index error
☞
By determining the vertical index error
the electronic level is adjusted automat-
ically
b
a
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c
ba
d
a Mechanical vertical axis of the
instrument, also called standing axis
b Plumb line
c Longitudinal component (l) of the
compensator index error
d Transversal component (t) of the
compensator index error
The compensator index errors (l, t) occur, if the vertical axis of the instrument and the plumb
line are parallel but the zero points of the compensator and the circular level do not coincide.
The calibration procedure electronically adjusts the zero point of the compensator.
☞
Line-of-sight error
Vertical index error
Compensator index error
Tools 39