Operating Instructions
LMS1xx Laser Measurement Sensors
Product description
8012471/ZN27/2017-06-09
© SICK AG · Germany · All rights reserved · Subject to change without notice
23
Chapter
3
3.6
Operating principle of the LMS1xx
The LMS1xx is an electro-optical laser measurement sensor that electro-sensitively scans
the perimeter of its surroundings in a plane with the aid of laser beams. The LMS1xx
measures its surroundings in two-dimensional polar coordinates. If a laser beam is incident
on an object, the position is determined in the form of distance and direction.
Fig. 4:
Measuring principle of the LMS1xx
Scanning takes place in a sector of 270°. The scanning range of the LMS1xx is type-
dependent maximum up to 50 m on light, natural surfaces (e.g. a white house wall).
Distance measurement
The LMS1xx emits pulsed laser beams using a laser diode. If such a laser pulse is incident
on an object or a person, it is reflected at its surface. The reflection is detected in the
receiver of the LMS1xx using a photodiode.
Fig. 5:
Principle of operation for pulse propagation time measurement
The distance to the object is calculated from the propagation time that the light requires
from emission to reception of the reflection at the sensor. This principle of “pulse pro-
pagation time measurement” is used by radar systems in a similar manner (see also
section 3.8.4 “Measured value output for a second reflected pulse” on page 38
Send pulse
Receive pulse
t
