Faster cycle times, better process control, reduced downtimes: these days system and machine management that ensures the optimal use of resources plays a critical role in the economic success of a business. Sensors, too, are an indispensable part of this success in automation technology. The comprehensive portfolio of sensors from Festo combines optimum performance and maximum reliability and ensures smooth and efficient production sequences.
A sensor converts a physical variable to be measured into an electrical one. This allows the electrical signals to be easily transmitted and further processed. The sensor can provide information on whether ...
The range of sensors from Festo includes, among others, cylinder sensors, pressure and vacuum sensors, flow sensors, opto-electrical and inductive sensors, as well as designs for special applications such as acids, food, cooling lubricants and much more.
Cylinder sensors are used to provide binary feedback on the piston position for pneumatic drives. They are sensors that detect the magnetic field of the piston magnet via a magnetic field sensor or reed contact. They are mounted in the required switching position in the cylinder slot and output a standardised 24 V switching signal when the magnetic field of the piston is detected.
An inductive proximity sensor is a sensor that operates contactlessly, i.e. it does not have any direct contact when responding to an approaching metal or galvanic object.
Position transmitters provide an analogue output signal in the sensing range. The contactless measuring principle ensures wear-resistant sensing, which is a particular advantage in harsh environments. As a further development of the binary cylinder sensor, position transmitters enable a range of new application areas when combined with pneumatic cylinders:
Pressure and vacuum sensors expand the application range of systems, provide greater process reliability and offer reliable monitoring. They are also easy and quick to use thanks to the standardised control and display concept of the Festo pressure sensors. Pressure and vacuum sensors measure the pressure applied at the pressure input of the sensor. A pressure measuring cell integrated in the sensor compares the excess pressure or low pressure applied to the sensor with the prevailing ambient pressure (relative pressure measuring cell) and outputs it as an electrical signal.
Pick & place machines are ready-to-install functional modules for repositioning, feeding and removing small parts in extremely confined spaces. The vacuum sensor uses a configurable threshold to detect whether the workpiece is being gripped securely so it can be moved reliably. The movement is force-guided via a linkage and enables very short cycle times. The assembly machines are designed to be used with electric, servo-pneumatic or pneumatic drives.
By monitoring the flow, a simplified diagnostic and condition monitoring process can be implemented: a change in the flow rate is often an indication that problems are likely to occur.
Application areas for Festo flow sensors:
Cylinder sensors for pneumatic drives form the starting point for the sensor range from Festo: they are tailor-made for Festo drives and the comprehensive portfolio covers solutions for all industry segments. From the position transmitter SDAT to pressure sensing with the pressure sensor SPAN and flow sensing with the flow sensor SFAH, the product portfolio from Festo covers the full range of classic sensor tasks for pneumatics.
All kinds of industries rely on sensors from Festo. This leads to a first-class partnership and the creation of application-optimised products in line with the needs and tasks of customers. These products help to increase productivity, improve process reliability, and enable Festo to offer many industries, such as the automotive industry or food industry, everything from a single source.
A sensor is a component that converts a measured physical variable or a chemical effect into an analogue electrical output signal. The physical variable is an input signal that is not electrical, such as pressure, weight, temperature, radiation, magnetic flow, speed or another physical variable.
There are different types of sensor, such as:
Festo sensors are used in a wide range of industries and help to increase productivity and process reliability. They enable Festo to offer many industries, such as the automotive industry or food industry, everything from a single source.
Proximity sensors or cylinder sensors are used to generate an output signal indicating that a piston has reached its end position. In connection with pneumatic cylinders, these sensors are also often referred to as pneumatic cylinder sensor or limit switches. There are different types of sensors, two general types of proximity sensors:
• Electrical/electronic sensors
• Pneumatic sensors or pneumatic cylinder sensors.
Within this group we distinguish different types of sensors:
Contact-type (electrical) sensors
Contact-type (electronic) sensors.
Contact-type (electrical) magnetic proximity sensors, reed switch sensor.
The contacts are opened and closed by the action of a magnetic field. Under normal conditions, the contacts of a reed switch are closed or open, depending on the design. Once the action of a magnetic field becomes strong enough, the contacts open or close. The sensor measures the piston. This sensor is an inductive sensor that measures ferrous metal (metal objects). For example, an inductive sensor cannot detect the position of a plastic object. For this, you need a capacitive sensor that generates an electromagnetic field. Every time an object or liquids come into the range of the measurement, the electric field changes.
Sensor detects when a cylinder piston reaches an end position, special cylinders are used whose pistons are equipped with a magnet. Proximity sensors are installed in the end positions. Once the piston and magnet reach this end position, the field of the magnet activates the sensors, generating an immediate sensor feedback for further processing.
Depending on the design of the sensor in question, its contacts will open (normally closed type) or close (normally open type) when the sensor is attenuated. The type of magnet mounted on the cylinder piston and the strength of the field must be matched to the sensors used and the installation conditions. Excessive distance between the magnet and the sensors, or the presence of interfering materials in the magnetic field, or vibrations can prevent reliable signal generation.
Contact sensors are used when high load currents need to be switched. However, these types of sensors operate noticeably slowly due to their physical contact and are thus not suitable for use at high switching frequencies.
Inductive sensors work with a high-frequency magnetic field on the active surface of the sensors. When a metal object or permanent magnet enters this magnetic field, the sensor's current consumption changes. This change is then electronically evaluated and converted into a signal.
A non-contact sensor is particularly used in cases where the signal is routed directly to a programmable logic controller (PLC) for further processing. Moreover, this type of sensor achieves a significantly longer lifetime than reed-switch sensors. An important factor regarding reliability is that electronic sensor is free from contact collision. During operation of contact-type sensors, small sparks may jump between the contacts just before they touch. This has the same effect as activating the contacts several times in a row and leads to the generation of false reading, detecting objects that are not there. This phenomenon is known as contact bounce. So-called welding current-resistant sensors are a special type of non-contact sensor and operate on the same principle as these. Their special feature is that their switching state does not change once the sensor enters an alternating magnetic field of the kind present on welding production lines.
There are two reasons why this type of sensor is used on cylinders. The first reason is that with very small cylinders, it is difficult to find enough space to install a separate proximity sensor for each end position. Secondly, it is sometimes necessary to detect a total of three positions, namely two end positions and an intermediate position. In the case of a gripper, for example, these could be the positions "open", "closed" and "workpiece gripped". A Hall sensor is an ideal tool for this purpose.
The method of operation: As with other proximity sensors, a permanent magnet attached to the cylinder piston is used, while the Hall sensor is mounted at a fixed location on the cylinder housing. When a magnetic field penetrates the Hall sensor, it generates a voltage that is proportional to the strength of the magnetic field and therefore to the position of the magnet. The Hall sensor outputs an analogue voltage corresponding to the instantaneous strength of the magnetic field.
This means that varying voltages are generated in the sensor over the entire stroke range of the cylinder, which can be correlated to individual piston positions. Adjustment is done in a similar way to conventional sensors. First, the sensor is mounted in a position covering almost the entire stroke range. Then the piston is moved to different positions and at the desired sensor positions, the signal is calibrated and adjusted on an electronic evaluation unit. The switching accuracy is about 0.2 mm. This means that a minimum distance of 0.5 mm is required between two positions for reliable detection.
A sensor with this technology is used when pneumatic output is required. These are essentially 3/2 valves switched by the magnetic field of the piston.
Electromechanical switches is a type of sensor that measures the movement of an object with physical contact. An object pushes against a switch and generates a circuit. Pressure and vacuum sensors measure compressed air pressure or compressed air vacuum. Flow sensors monitor the flow rate and are important in the industry to measure energy consumption or give an alarm. An optical sensor measures colours or object.
Motion sensor, analog sensors, temperature sensors, liquids detecting, humidity sensors, passive sensors, image sensor, light sensor, sound waves, light intensity, current, radiation ... is a technology that is not built at Festo.