Page 653 - Sensors and Systems - North American Catalog
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Ultrasonic Sensors
3
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Refer to General Notes Relating to Product Information
Pepperl+Fuchs Group
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Copyright Pepperl+Fuchs
Ultrasonic Sensors
Introduction
6. Installation and operation
Ultrasonic sensors can be installed and operated in any location. However,
excessive exposure to dust or dirt should be avoided. When cleaning the
ultrasonic sensors, make sure that the sensor area (decoupling layer)
and the integral foam surrounding the converter are not damaged. Water
drops or crusting on the decoupling layer will impair the functioning of the
ultrasonic sensor. Light deposits of dust are not critical.
Actuating direction
The objects to be detected can enter the sound beam from all sides. The
anticipated trip points are defined based on the detection ranges and
response curves specified in the data sheets.
Deflection of the beam angle
The beam angle can be deflected using smooth, even reflectors. However,
the signal may not be deflectedmore than twice because the signal damping
that occurs with each deflection reduces the detection range.
Note:
The reflector areas must be accurately aligned. For some of its sensor
types, Pepperl+Fuchs offers reflectors designed for 90° angle deflection.
Mutual interference
To prevent mutual interference, the minimum distances between sensors
with the same detection range must be taken into account, as specified in
the following graphics.
X
m
X
m
X
Detection range
mm
Detection range
mm
to 500
to 2000
to 4000
to 6000
> 0.3
> 1.0
> 2.0
> 2.5
The specified values are to be taken as guidelines. They apply if the beam
angles are aligned parallel to one another and the object surfaces are located
at right angles to the axes of the beam angle. The actual required spacing
“X” depends on the alignment, the type of target to be detected, and the
conditions relating to other objects that are located in the beam angle.
X
The distances specified below must be taken into account when mounting
sensors opposite one another.
X'
m
X'
m
X'
Detection range
mm
Detection range
mm
to 500
to 2000
to 4000
to 6000
> 2.0
> 8.0
> 16.0
> 25.0
If interference occurs, it may be necessary to increase the spacing “X” or
activate the synchronization feature, if available. Pepperl+Fuchs offers a
series of sensors equipped with synchronization inputs for this purpose.
These sensors can be used in synchronized or multiplex mode.
Synchronization can be achieved with an external synchronization signal
or with self-synchronization for some sensor types. Synchronized and
unsynchronized sensors must not be mounted opposite each other.
Avoiding interference
If several sensors operate in very close proximity to each other, they can cause
mutual interference, meaning that reliable detection is no longer possible.
Synchronizing the transfer cycles for all sensors makes it possible to reduce
the minimum distance between the sensors and eliminate the interference.
Multiplex mode
Operating the sensor in multiplex mode provides a way to stagger the
ultrasonic bursts in order to eliminate the possibility of two or more units
from sending or receiving signals at the same time.
