Guidelines For Special Measurement Situations - Leica LS10 User Manual

5.2
Special
Measurement
Situations
LS10/LS15, Measurement Guidelines

Guidelines for Special Measurement Situations

Vibrations
Touch the upper third of the tripod to reduce the vibrations at the instrument, for
example caused by wind.
Back light
Low sunlight may influence the ability of the instrument to read the staff. Use the
sunshade delivered with the instrument to shield the objective.
Darkness
When working in darkness (for example tunnelling), evenly illuminate the measuring
area of the staff with a flashlight or a spotlight or use a special self-illuminated staff
(for example Nedo Lumiscale).
Measuring at the lower end of the staff
Measurements slightly below the zero point of a staff are possible and will result in
negative measurement values.
Measuring at the upper end of the staff
When measuring at the upper end of the staff, use staffs with the following lengths:
• 4.05 m
• 2.95 m
• 2.70 m
• 1.95 m
• 1.82 m
With other staff lengths, measurements at the upper end of the staff are not possible.
Code length required in the field of view

For exact measurements, the centre area in the field of view should be free of
any interfering cover.
The following code lengths are required in the field of view, depending on the distance
to the staff.
Distance
0 m - 10 m
10 m - 50 m
50 m - 90 m
90 m - 110 m
Shade
Normally, shade patterns on the staff do not affect the measurement results.
However, avoid dark shade, as it can have the same effect as an interfering cover on
the field of view.
Focus
A slightly unfocused image does not influence the measuring time and the accuracy.
When large focus errors occur, the instrument stops the measurement. On LS15
instruments, the Autofocus routine is based on the maximum contrast of code on the
instruments sensor. If the reticle is not adjusted to the eyesight of the user, this may
lead to the impression of an incomplete auto focussing. For details on how to adjust
the reticle to the eyesight, refer to "4.3 Instrument Setup".
Measuring through window panes
Avoid measuring through window panes.
Precision mode for line levelling
If a line levelling job requires high accuracy, activate the precision mode. Refer to
"7.4.3 Setting Tolerances".
Code length
100%
80%
70%
60%
Cover
0%
20%
30%
40%
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