Distance sensors – find manufacturers and suppliers

Distance sensors detect the distance between a sensor and an object, either without physical contact or by means of tactile measurement.

They are used to determine positions, detect the presence of objects, monitor fill levels, prevent collisions or control movements within automated machines and systems.
Depending on the measuring principle, distance sensors operate optically, acoustically, inductively, capacitively, magnetically or mechanically. This allows them to be adapted to different materials, measuring ranges, accuracy requirements and environmental conditions.
Typical applications can be found in mechanical and plant engineering, automation technology, robotics, conveyor technology, warehouse logistics, vehicle technology and quality assurance.
The following provides an overview of typical designs, applications, advantages and important selection criteria for distance sensors.

Types of distance sensors

Optical distance sensors

Optical distance sensors use light to determine the distance to an object.
Depending on the design, they operate with laser light, infrared light or visible light. The distance is determined using methods such as triangulation, time-of-flight measurement or phase-shift measurement.
Optical sensors often provide high accuracy and fast measurements. They are suitable for positioning tasks, height measurements, presence checks and quality inspections.
However, the measurement can be affected by surface colour, gloss, transparency, ambient light or contamination.

Laser sensors

Laser sensors are optical distance sensors with a particularly small and clearly visible measuring spot.
They are therefore suitable for precise measurements on small objects, edges or areas that are difficult to access.
Depending on the measuring range and design, laser sensors can detect both short and longer distances.
For reflective, transparent or very dark surfaces, it must be checked whether the selected measuring method operates reliably.

Ultrasonic sensors

Ultrasonic sensors emit sound pulses and measure the time taken for the reflected signal to return.
The distance to the object is calculated from this time of flight.
As the measurement does not depend on colour or optical transparency, ultrasonic sensors are also suitable for dark, glossy or partially transparent materials.
They are used for fill level measurement, object detection and distance monitoring, among other applications.
Temperature, air movement, soft surfaces or unfavourable object shapes can influence the measurement result.

Inductive distance sensors

Inductive distance sensors detect the distance to metallic objects through changes in an electromagnetic field.
They operate without contact, are robust and are well suited to industrial environments.
Typical applications include detecting the position of metallic components, monitoring machine elements and measuring short travel distances.
Compared with optical or ultrasonic sensors, their measuring range is usually limited and depends on the material of the target object.

Capacitive distance sensors

Capacitive distance sensors detect changes in an electric field.
They can detect both metallic and non-metallic materials, including plastics, glass, wood, powders and liquids.
This makes them suitable for distance measurements, fill level monitoring and the detection of thin material layers.
Humidity, contamination and changes in material properties can affect the measurement.

Magnetic distance sensors

Magnetic sensors detect position or distance using a magnetic field.
They are used, for example, on cylinders, linear units, flaps or moving machine components.
Depending on the design, they operate with reed contacts, Hall sensors or magnetoresistive measuring methods.
They are particularly suitable for applications in which the object to be detected can be equipped with a magnet.

Mechanical distance sensors

Mechanical distance sensors use a tactile measuring element.
They are used where direct contact is permissible or specifically required.
These sensors can provide highly accurate travel and position information, but are subject to mechanical wear.
They are suitable for inspection tasks, end-position monitoring and measurements on solid surfaces.

Applications of distance sensors

Mechanical and plant engineering

In mechanical engineering, distance sensors detect the position of workpieces, tools, slides and other moving components.
They can monitor end positions, check machining distances and control movements within automated processes.
Non-contact sensors are particularly advantageous where high cycle rates or wear-free measurement are required.

Automation and assembly technology

In automated assembly systems, distance sensors detect whether components are correctly positioned, fully inserted or present at the intended height.
They can monitor gripper movements, control feeding processes and identify defective workpieces at an early stage.
Short response times and reliable connection to the control system are particularly important.

Robotics and handling technology

Robots use distance sensors for object detection, positioning and collision avoidance.
They support approach movements towards workpieces, the detection of gripping positions and the monitoring of safety distances.
Fast measurements and low latency are required for dynamic movements.

Conveyor and warehouse technology

In conveyor systems, distance sensors detect containers, packages, pallets and other transported goods.
They monitor the distances between objects, detect congestion and support positioning at transfer points.
In warehouse systems, they can also be used for height measurement, storage location occupancy and collision avoidance.

Fill level measurement

Distance sensors determine the distance between the sensor and the surface of a medium.
This value can be used to calculate the fill level in containers, tanks or silos.
Ultrasonic and optical sensors are frequently used for non-contact measurements.
Suitability depends on the medium, surface characteristics, vessel geometry and environmental conditions.

Quality inspection and metrology

In inspection and measuring systems, distance sensors detect the height, thickness, flatness or deformation of components.
Several sensors can be used to determine differences, profiles or parallelism.
High accuracy, repeatability and stable signal processing are essential for these applications.

Vehicle and mobile technology

Distance sensors are used in vehicles and mobile machinery for obstacle detection, positioning and monitoring movement areas.
In these applications, they often have to withstand vibration, temperature fluctuations, moisture and contamination.

Advantages of distance sensors

• Non-contact detection of positions and distances

• Reduced mechanical wear

• Fast measurement of moving objects

• Suitability for different materials and surfaces

• Integration into automated control processes

• Monitoring of end positions, fill levels and safety distances

• High repeatability when correctly specified

• Detection of small objects and minor changes in distance

• Support for quality control and process monitoring

• Adaptation to short and long measuring ranges

Important selection criteria for distance sensors

Measuring range

The required measuring range depends on the shortest and longest distance that must be detected reliably.
In addition to the nominal measuring range, possible tolerances, vibrations and variations in object position must also be considered.
A sensor should not be operated continuously at the extreme limits of its measuring range.

Accuracy and repeatability

The required accuracy depends on the application.
For simple presence detection, approximate distance information is often sufficient. Measuring and positioning tasks may require significantly higher resolution and repeatability.
Temperature drift, linearity deviation and measurement noise must also be considered.

Material and surface of the target object

The measuring principle must be suitable for the target object.
Inductive sensors are only suitable for metallic materials. Optical sensors can be affected by colour, gloss or transparency. Ultrasonic sensors require a sufficiently reflective surface.
Before selection, the materials, colours and surfaces that will actually occur should therefore be checked.

Response time and measuring frequency

Fast-moving objects and short machine cycles require sensors with short response times and a high measuring frequency.
A lower measuring rate is often sufficient for slowly changing fill levels or positions.
The sensor performance must be matched to the process speed and the response time of the control system.

Measuring spot and detection area

Optical sensors have a defined light spot, while ultrasonic sensors usually have a cone-shaped detection area.
The measuring area must be designed so that the intended object is detected reliably without also detecting neighbouring components.
A small measuring spot is particularly important for small objects, narrow gaps or structured surfaces.

Environmental conditions

Dust, moisture, oil, vibration, temperature fluctuations and electromagnetic interference can affect the measurement.
Sensors must therefore have a suitable degree of protection, mechanical strength and temperature resistance.
Special housing materials and approvals may be required for hygienic, potentially explosive or aggressive environments.

Output signal and interfaces

Depending on the design, distance sensors provide switching signals, analogue measured values or digital process data.
A binary output is often sufficient for simple presence detection. Analogue or digital measured values are required for continuous distance measurement.
The interface must be compatible with the existing controller, evaluation unit or fieldbus environment.

Installation and alignment

The installation position influences measurement reliability.
The sensor must be mounted securely and aligned so that the measuring signal reaches the target object under suitable conditions.
Vibrations, changing angles or obstacles within the measuring field can lead to measurement errors.

Parameterisation and diagnostics

Adjustable sensors allow the measuring range, switching points, filtering and output behaviour to be adapted.
Easy-to-use parameterisation simplifies commissioning and adjustment to changing products.
Diagnostic functions can provide early warnings of contamination, signal loss or unsuitable measuring conditions.

Summary

Distance sensors detect the distance between a sensor and an object and provide important information for control, positioning, monitoring and quality assurance.
Depending on the application, optical, acoustic, inductive, capacitive, magnetic or mechanical measuring principles are used.
The main selection criteria include measuring range, accuracy, target material, response time, environmental conditions and interfaces.

Distance sensors are available from various manufacturers and suppliers. Comprehensive information about manufacturers and suppliers of distance sensors from around the world can be found on Exportpages.