Leica Geosystems TPS110C - Manual (Page 34)

Measuring 34
Distance measurement, continued
A laser distancer (EDM) is
incorporated into the
instruments of the TPS110
series.
In all versions, the distance can
be determined by using an
invisible infrared beam which
emerges coaxially from the
telescope objective.
Measurements to
strongly reflecting
targets such as to traffic lights
in infrared mode without
prism should be avoided. The
measured distances may be
wrong or inaccurate.
For applications without
reflector, the TCR-version also
use a visible red laser beam
which emerges in the same
manner.
When a distance
measurement is
triggered, the EDM
measures to the object which
is in the beam path at that
moment.
If e.g. people, cars, animals,
swaying branches, etc. cross the
laser beam while a measurement
is being taken, a fraction of the
laser beam is reflected and may
lead to incorrect distance values.
Avoid interrupting the measuring
beam while taking reflectorless
measurements or measurements
using reflective foils.
Measurements to prism
reflectors are only critical if an
object crosses the measuring
beam at a distance of 0 to 30m
and the distance to be measured
is more than 300m.
In practice, because the
measuring time is very short, the
user can always find a way of
avoiding these critical situations.
1
100z46
1
100z47
Incorrect result
Correct result