20
Operating the Instrument
Leica TPS800-4.0.0en
Distance measurement
A laser distancer (EDM) is incorporated into the
instruments of the TPS800 series.
In all versions, the distance can be determined by
using an Laser beam which emerges coaxially from
the telescope objective.
)
Measurements to strongly reflecting
targets such as to traffic lights in Reflector EDM
mode without prism should be avoided. The
measured distances may be wrong or inaccu-
rate.
For applications without reflector a special arrange-
ment of the EDM, and appropriate arrangement of
the beam paths, enable ranges of over five kilome-
tres to be attained with standard prisms.
Miniprisms, 360° reflectors and reflector tapes can
also be used, and measurement is also possible
without a reflector.
)
When a distance measurement is trig-
gered, 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.
)
Very short distances may be measured
reflectorless in IR mode to well reflecting targets.
Note that the distances are corrected with the addi-
tive constant defined for the active reflector.
