Figure 7: Angle of reflection
Retroreflection
If the reflective energy is greater than 100%, the beam is not reflected diffusely in all
directions; instead it is reflected in a targeted way (retroreflection). Thus a large part of
the emitted energy can be received by the laser distance measurer. Plastic reflectors
(cat’s eyes), reflective tape, and triple prisms have these properties.
Figure 8: Retroreflection
Reflective surfaces
The laser beam is almost completely deflected on reflective surfaces. This means that
an object hit by the deflected beam may be detected instead of the reflective surface.
Figure 9: Specular surfaces
Small objects
Objects that are smaller than the diameter of the laser beam cannot reflect the laser
light’s full energy. The portion of the light beam that does not reach the object is lost. If
all of the light reflected to the sensor is insufficient, the object may not be detected.
The portion of the light that does not reach the front object can be reflected by a larger
object in the background. If all of the light reflected to the sensor is sufficient, this
object is detected. This can lead to a corruption of the measured value.
If the All echoes or Last echo option is selected, the portion of the light that does not
reach the front object, but is reflected from a rear surface, can produce a second echo
.
PRODUCT DESCRIPTION
3
8013796/1ALS/2021-03 | SICK
O P E R A T I N G I N S T R U C T I O N S | LMS5xx
19
Subject to change without notice
