elobau Ultrasonic Sensors

Precise, flexible, reliable

Precise measurements are essential in many areas, in the fields of technology and medicine, for example. Thanks to the help of ultrasound and corresponding sensors, results can be achieved that other methods do not provide. Consequently, ultrasound technology is not only effective but also remarkably straightforward.

ultraschallsensoren
APPLICATIONS & PRODUCT LINE-UP

Our Multipurpose Products

Suitable solutions for every Application

A sensor emits sound waves from the high-frequency ultrasonic range, that are reflected by the target object and then received again by the sensor. Based on the duration of this process, the distance can be calculated. In this way, both distances can be measured, as well as the position of any desired object. This makes the ultrasonic sensor a real all-rounder, the ideal tool for numerous measuring and control tasks in the industry and beyond.

elobau sensors come in three different cylindrical designs, so that they can be easily integrated into any machine. Furthermore, they offer flexible operating modes. When combined with various digital or analogue outputs, they provide suitable solutions for almost any application.

Even narrow installation environments are not a problem, as cross-talk among the sensors is avoided due to reliable synchronization and multiplexing, thereby ensuring error-free operation. The wide range of applications of elobau ultrasonic sensors requires additional expansion, through the fulfilment of the ATEX guidelines for potentially explosive atmospheres.

Last but least, in contrast to products from other companies, elobau ultrasonic sensors are coated with ceramic. This coating ensures even better transmission behaviour from the sensors when sending and receiving signals.

guidance

Atex

Better safe, than Sorry

Even narrow installation environments are not a problem, as cross-talk among the sensors is avoided due to reliable synchronization and multiplexing, thereby ensuring error-free operation. The wide range of applications of elobau ultrasonic sensors requires additional expansion, through the fulfilment of the ATEX guidelines for potentially explosive atmospheres.

functionality

What is an Ultrasonic Sensor and how does it work?

In most cases, an ultrasonic sensor is both the transmitter and receiver. The measurement principle is simple. The sensor sends short, high-frequency sound pulses in cyclic intervals, in the direction of the target object, which propagate through the air at the speed of sound. When they hit the target object, they are reflected there and return to the sensor as an echo. The integrated electronics then calculates the distance from the time span between transmission and receiving.

One advantage of this is that the sensors have excellent object background suppression, as the distance to the object is calculated with a sound runtime measurement instead of with intensity measurement.

By using distance measurement, ultrasonic sensors are able to measure objects made of different materials such as metal, plastic or wood. The colour of the object plays no role in this. Even surfaces as clear as glass or thins wires and films present no problem. With elobau products, dusty air, paint mist or thin deposits on the sensor don’t lead to faulty measuring results.

types

What types of Ultrasonic Sensors are there?

There are ultrasonic sensors for different operating modes; diffuse reflection sensors, reflective barriers and throughbeam sensors.

    Diffuse Reflection Sensor

    The use of diffuse reflection sensors is the most common ultrasonic sensor operating mode. Transmitters and receivers of ultrasonic waves are positioned together with the electronics used for evaluation in a single housing. For measurement, these models require a reflection, that is sent to back to the sensor from the target object. If an object enters the sensor’s switching area, an echo from the object triggers the switching operation.

    Retro-Reflective Sensor

    In the retro-reflective sensor operating mode, the ultrasonic sensor functions as both transmitter and receiver. However, the ultrasound signal, in contrast to the sensor, is permanently thrown back from a fixed reference reflector. This reflector can be an appropriately arranged metal or plastic plate. Other backgrounds that are present in the setting such as walls, floorboards or conveyor belts are also considered reflectors.

    If there is no object between the sensor and the reflector, the ultrasonic sensor constantly receives the same echo, without triggering a reaction. If an object is introduced between the sensor and reflector and can now be detected, there are basically three different ways to initiate a switching operation.

    A small object is in front of the reference reflector, that is detected by the sensor. Furthermore, the sensor receives an echo from the reflector.

    A large object is slid in front of the reflector and covers it completely. So the sensor only receives an echo signal from the large object, but not from the reflector.

    A large object is in front of the reflector, covering it in such a way that it cannot however be detected by the sensor, because it is oblique, for example. In this case, the ultrasonic sensor receives no signal, neither from the object nor the reflector.

    All three outlined situations trigger a pre-defined switching operation at the sensor output. A retro-reflective sensor of this type is above all suitable for detecting sound-absorbing objects. Otherwise, it can also be used to differentiate between objects with surfaces that are hard to detect against other surfaces, perhaps if the surface is at an angle to the signal path.

    Throughbeam Sensor

    In contrast to the two operating modes named, with the throughbeam sensor, two ultrasonic sensors are required. One of these serves as a transmitter, the other as a receiver, where the electronics for evaluation is also housed. Both sensors are in separate housings. Installation takes place opposite on one axis. If an object is now introduced between the sensors and interrupts the sound beam, the output of the receiver sensor triggers a switching operation.

    Generally, the sensitivity of the receiver can be individually adjusted in order to enable installation in different distances between the transmitter and receiver, or to make different-sized objects recognisable.

    This operating mode offers some advantages. First of all, it is particularly resistant to influences and disturbances. Secondly, the range of the sensors can be doubled. Reliable registration of objects is also no problem, even with significantly larger distances between the sensors. Thirdly, the result is a higher switching frequency or faster response, as constant switching between sending and receiving is no longer necessary.