598
Ultrasonic Sensors
3
Ultrasonic Sensors,
Thru-Beam Sensors,
cylindrical
3
.2
Ultrasonic Sensors,
Diffuse Mode Sensors,
cylindrical
3
.1
Ultrasonic Sensors,
Thru-Beam Sensors,
rectangular types
3
.2
Ultrasonic Sensors,
Diffuse Mode Sensors,
rectangular types
3
.1
Ultrasonic Sensors,
Sensors for Separate Evaluation
3
.3
Ultrasonic Sensors,
Double Sheet Sensors
3
.4
Ultraschallsensoren,
Ultrasonic Sensor Accessories
3
.5
Germany: +49 621 776-4411
Consider the General Notes on the Information in the Pepperl+Fuchs Product Catalogs
Pepperl+Fuchs Group
fa-info@de.pepperl-fuchs.com
USA: +1 330 486 0001
fa-info@us.pepperl-fuchs.com
Singapore: +65 6779 9091
fa-info@sg.pepperl-fuchs.com
Copyright Pepperl+Fuchs
Synchronization ports connected
The sensors are activated on a cycle over a short period. It should be
noted that with this operation mode, the multiplex time T is extended by
factor N, where N indicates the number of sensors operated in multiplex
mode.
T multiplex = N x T sensor and f sync = 1/T multiplex
If different types of sensors are used, the entire cycle time equates to the
total of the cycle times for the individual sensors.
Tmultiplex = T 1 + T 2 +T 3 ... + T N
When using self-synchronization, the sensors operate in multiplex mode.
Synchronized mode
Synchronization ports conneted
external clock
In this operating mode, the synchronization inputs for all sensors are
linked and are controlled collectively by an external clock-pulse source.
In contrast to multiplex mode, this does not increase the cycle time. Syn-
chronization mode is suitable for monitoring larger areas but is also useful
in confined spaces because little distance is required between the sen-
sors.
The distances specified below must be taken into account when mount-
ing 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
Measuring plates/objects
Ultrasonic sensors can detect solid, liquid, and granulated objects. The
surface properties of the object are important for the evaluation of the
echo by the sensor. All level and flat surfaces that are positioned at a
right angle to the beam angle enable an ideal reflection. The measuring
plate may have a maximum angle deviation of +/- 3º in order to guarantee
reliable detection.
3
˚
3
˚
Material properties such as transparency, color, or surface treatment
(
shiny or matt) do not affect detection reliability. Rough surfaces result in
diffuse reflection of a portion of the sound energy, which decreases the
detection range.
However, the roughness of the surface allows for greater angle deviation
due to the predominantly diffuse reflection of the ultrasonic signal. This
enables detection of the filling level or angle of repose for granular materi-
als with an angle deviation of up to 45° (with reduced detection range).
The following objects are suitable for detection:
•
All flat and fixed objects that are aligned at a right angle to the beam
angle
•
All fixed objects that are randomly aligned and have a rough surface
that causes a diffuse reflection
•
Surfaces of fluids at an angle of < 3° from the axis of the beam angle
The following materials are not suitable:
•
Materials that absorb ultrasonic signals such as felt, cotton, rough
textiles, or foam
•
Materials with temperatures exceeding 100 °C
Sensors with an adjustable beam angle width
Some series offer an adjustable beam angle that enables the sensors
to be used in confined spaces where objects can be spread out laterally
in the beam angle. Such conditions would result in inaccurate switching
characteristics or incorrect readings for sensors that do not include this
function. Adjusting the shape of the beam angle does not affect the maxi-
mum detection range.
0
200
400
600
900
1000
400
300
200
100
0
-100
-200
-300
-400
X
Y
Characteristic response curve
Distance X [mm]
DistanceY [mm]
flat surface 100 mm x 100 mm
round bar, Ø 25 mm
wide sound lobe
narrow sound lobe
The graphic above illustrates the characteristic response curve of sensor
UB500-F42 for two different objects:
•
Rod with 25 mm diameter (lower part) and
•
Level area measuring 100 mm x 100 mm (upper part).
It can be seen that the selection of a slim beam reduces the radial detec-
tion range. As a result, the sensor can be mounted in confined spaces.
Ultrasonic Sensors
