Types of sensors and their use in industry
What are sensors?
Sensors are devices or instruments used to detect physical, chemical or biological properties of the environment and convert them into measured values. They play a crucial role in various applications, from industrial automation and medicine through to environmental monitoring. autosen sensors are used in industry, where they contribute to automating a wide range of systems. For example, they detect the positions of objects, measure and monitor process values such as levels and temperatures, or enable effective and cost-efficient maintenance through condition monitoring on machines.What is sensor technology?
Sensor technology refers to the field of research concerned with the development, application and evaluation of sensors. Sensors are devices or instruments that capture physical or chemical signals from the environment and convert them into measurable data. This data can then be used for monitoring, control or analysis in various applications.There are many types of sensors that can detect different kinds of signals, including light, temperature, pressure, sound, movement, humidity and much more. These sensors are used in a wide range of fields, including the automotive industry, medicine, environmental monitoring, industrial automation, robotics and many others.
Sensor technology is an interdisciplinary field that includes aspects of electronics, physics, chemistry, computer science and engineering. Advances in sensor technology help to improve process efficiency, reduce costs, increase safety and enable new technologies.
In industry, a wide variety of sensors are used to monitor different parameters and ensure the smooth running of production processes and product quality.
A sensor, usually a piezoelectric sensor or a pressure sensor, detects vortex formation and shedding and measures the frequency of vortex formation. From this frequency, the flow value can be calculated by using the known relationship between vortex frequency and fluid velocity.
Inductive sensors
Inductive sensors use the principle of electromagnetic induction to detect metallic objects. An alternating current flowing through a coil generates an electromagnetic field. The presence of a metal object nearby influences this field, and the sensor outputs an electrical switching signal. In industry, inductive sensors are often used for contactless detection of metal parts in manufacturing systems, for example in conveyor systems, assembly lines, or for position detection of workpieces.Ultrasonic sensors
Ultrasonic sensors emit high-frequency sound waves and measure the time it takes for the sound waves to be reflected by an object and return to the sensor. The measured time is then used to calculate the distance between the sensor and the object. In industry, ultrasonic sensors are often used for contactless measurement of distances, levels in tanks or silos, as well as for detecting grilles and transparent objects.Optical sensors
Optical sensors use light to detect objects or measure the distance to an object via time-of-flight measurement. In industry, optical sensors are often used for position detection, distance measurement, or capturing labels or codes on packaging. This enables processes to be controlled without contact and over longer distances.Capacitive sensors
A capacitive sensor measures changes in electrical capacitance. When an object approaches the sensor, the capacitance of the electric field changes, which is detected by the sensor. In industry, capacitive sensors are often used for contactless detection of materials, level measurement of liquids, and position detection of objects in automated production lines. Unlike inductive sensors, capacitive sensors also detect water, oils, powders and much more.Cylinder switches
Cylinder switches, also known as proximity switches or limit switches, are used in industry to detect the presence or position of pistons in cylinders. These switches often use a magnetic measuring principle. Industrial application examples include detecting the end position of pneumatic or hydraulic cylinders in machines, which is important for process control and ensuring safety.Magnetic sensors
Magnetic sensors with GMR (Giant Magneto-Resistance) cells use the GMR effect, which describes a change in electrical resistance in a material under the influence of an external magnetic field. In a magnetic sensor with GMR cells, the change in resistance is measured and used to detect magnetic fields. In industry, these sensors are used for precise position detection, magnetic encoders and speed measurement in various applications, including controlling conveyor belts, robots and automation systems.Pressure sensors
Pressure sensors detect pressure changes in a system and convert them into electrical signals. This is often done using strain gauges or piezoelectric materials that change their electrical properties under pressure. In industry, pressure sensors are used to monitor fluids in hydraulic systems, to control compressed air in pneumatic systems, in medical technology for blood pressure measurements, and in many other applications for precise pressure measurement.Flow sensors
Flow sensors measure the amount of liquid or gas flowing through a pipe or line. Various technologies can be used, such as electromagnetic, ultrasonic, vortex or calorimetric measuring principles. In industry, flow sensors are used to monitor liquid flows in pipelines for process control, in heating and air-conditioning systems, in the food industry for dosing applications, and in the chemical industry for accurate liquid dosing.Level sensors
Level sensors measure the level or quantity of a medium, often liquids, granulates or powders, in a tank or another type of container. They use various technologies such as pressure measurement, ultrasound or capacitive sensors to determine the level. In industry, level sensors are used in applications such as tank monitoring, material dosing, wastewater management and warehouse management to measure and control substance levels accurately.Temperature sensors
Temperature sensors monitor the temperature of a medium and convert it into electrical signals. They use various technologies such as thermocouples, resistance thermometers or infrared radiation to detect temperature changes. In industry, temperature sensors are widely used, for example in process control of chemical plants, in food processing for temperature monitoring, in HVAC and refrigeration technology, as well as in quality assurance in the production of electronic components.Humidity sensors
Relative humidity sensors measure the moisture content in the air, usually using a capacitive measuring principle. The capacitance changes in accordance with the water content in the air, so an electrical signal can be output that changes with the humidity. In industry, relative humidity sensors are used in applications such as controlling production environments, warehousing, HVAC systems, as well as in laboratories for precise humidity monitoring.Vibration sensors
Vibration sensors, also known as vibration or acceleration sensors, measure the vibrations or accelerations of an object. They use internal components such as piezoelectric crystals or MEMS to convert these movements into electrical signals. In industry, vibration sensors are used to monitor the condition of machines and systems in order to detect irregularities early, prevent failures and optimise maintenance. Examples include monitoring rotors in wind turbines, motors in manufacturing, or storage and handling machines in logistics.AC current sensors
AC current sensors, also known as current transformers, detect the alternating current flow in a conductor and convert it into a proportionally measurable signal. These sensors can be based on different principles, such as a Rogowski coil or a ferrite core. In industry, AC current sensors are used to monitor electrical currents in lines to measure energy consumption, detect overloads and optimise the efficiency of electric motors or other electrical devices.Inclination sensors
Inclination sensors, also known as inclinometers or tiltmeters, detect the angle difference between the force of gravity and the measured direction. They use various technologies, such as MEMS (micro-electro-mechanical systems) or liquid pendulums, to measure inclination. In industry, inclination sensors are used in applications such as aligning construction machinery, monitoring off-road vehicles, measuring inclination on lifting platforms, or aligning solar panels.Speed sensors
Speed sensors with inductive operation measure the rotational speed of metallic gear wheels or objects by measuring changes in magnetic flux caused by rotation. In industry, inductive speed sensors are used to monitor motor speeds, control conveyor belts, in the automotive industry to measure wheel speeds for ABS systems, and in other applications where detecting rotational speed is crucial.Capacitive hand actuators
Capacitive hand actuators work by changing capacitance when a person touches the button with their hand. The touch changes the capacitance of the button, which is detected by a sensor. In industry, capacitive hand actuators are often used to operate machines, control manufacturing processes and as contactless control elements in environments with special requirements, such as clean rooms.Types of sensors and their use in industry
In industry, a wide variety of sensors are used to monitor different parameters and ensure the smooth running of production processes and product quality.Sensors in Industry 4.0
In Industry 4.0, sensors play a central role because they enable real-time data acquisition and monitoring. Industry 4.0 refers to the fourth industrial revolution, which is characterised by the integration of digital technologies into industrial production. Sensors are crucial for implementing the principles of Industry 4.0, which promote a connected, flexible and intelligent manufacturing environment.Benefits of sensors in Industry 4.0:
- Data acquisition and real-time monitoring: sensors continuously measure data from various production processes. This real-time data enables precise monitoring and control of machines and systems.
- Networking and communication: sensors are networked and communicate with each other as well as with other devices and systems. This enables seamless integration of production steps and improves collaboration between machines.
- Predictive maintenance: sensors monitor the condition of machines and systems, helping to ensure smooth operation. By analysing the collected data, predictive maintenance models can be created to forecast maintenance needs and reduce unplanned downtime.
- Quality control and improvement: sensors monitor quality parameters during the manufacturing process. Deviations can be detected and corrected immediately, leading to higher product quality.
- Flexibility and adaptability: sensors enable flexible production because they can quickly adapt to changes. This is particularly important in environments with custom production and small batch sizes.
- Automation and robotics: sensors are an integral part of robots and automated systems. They enable precise movements, object detection and safe collaboration between humans and machines.
- Increased efficiency: by continuously monitoring and optimising processes, sensors help to improve the efficiency of the entire value chain.
Active and passive sensors
Active and passive sensors differ mainly in their measurement method and signal processing.
Active sensors:
Power source: active sensors require their own power source to generate and transmit signals.
How it works: they actively transmit signals and capture the reflected or backscattered signals. The measurement is based on the return or change of the transmitted energy.
Example: an ultrasonic sensor emits sound waves and measures the time required for the reflected waves to return.
How it works: they actively transmit signals and capture the reflected or backscattered signals. The measurement is based on the return or change of the transmitted energy.
Example: an ultrasonic sensor emits sound waves and measures the time required for the reflected waves to return.
Passive sensors:
Power source: passive sensors do not require their own power source and instead use natural phenomena or existing energy sources.
How it works: they measure natural radiation or energy emitted by objects or environments without actively transmitting signals.
Example: a PT100 measuring resistor changes its electrical resistance depending on the temperature. An evaluation unit evaluates the resistance or converts it into a standardised electrical signal.
How it works: they measure natural radiation or energy emitted by objects or environments without actively transmitting signals.
Example: a PT100 measuring resistor changes its electrical resistance depending on the temperature. An evaluation unit evaluates the resistance or converts it into a standardised electrical signal.
