Position sensors

What are position sensors?

Position sensors are high-precision electronic components that continuously detect the exact position and movement of objects. These intelligent sensor systems operate either non-contact or via direct contact. They convert mechanical changes in position into electrical signals that can then be analyzed. In modern automation technology, they ensure precise control, safety, and quality in production processes.

Modern machines require highly complex motion sequences with the utmost precision. Without precise position feedback, automated production lines or robotic systems would not be able to function. Position sensors measure various parameters:

• Distance traveled and stroke lengths
• Direction of motion and speed
• Current location
• Acceleration and deceleration

How Position Sensors Work

Position sensors operate on various physical principles. Potentiometric sensors are contact-based and function as voltage dividers. Magnetic sensors utilize changes in magnetic fields, while inductive sensors use electromagnetic fields to determine position.

However, the basic principle remains the same. A physical change is converted into an electrical signal that can be processed by control systems.

Position Sensor Technologies

Potentiometric position sensors

A potentiometer sensor is an electromechanical position or angle sensor. It Voltage the position of an object into an electrical Voltage , thereby measuring linear or rotational movements.

Its operation is based on the principle of a voltage divider. The component has three terminals: two supply terminals at the ends of the resistor path and a movable sliding contact, known as the wiper. When the slider is moved, for example by turning or sliding it, the resistance values between the slider and the supply terminals change
This change in resistance is then measured as a change in voltage and converted into an electrical signal. This allows the exact position of the moving part to be determined.

The potentiometer thus provides direct and, as a result, unbeatably fast position feedback without the need for complex electronics. It is cost-effective while offering high measurement accuracy and excellent temperature stability. Our proprietary material formulation ensures a long service life.

Magnetic position sensors

Magnetic position sensors have proven to be particularly robust and reliable. They use permanent magnets or magnetic fields for non-contact position detection. This technology offers significant advantages in demanding industrial environments, as it is resistant to contamination and high temperatures.

Technical advantages: 

• Operating range from -40 °C to +150 °C
• Resistant to dirt, oil, and moisture
• Maintenance-free design with no wear parts
• Easy installation

Inductive position sensors

Inductive sensors operate on the principle of electromagnetic induction. Since moving parts operate without physical contact, wear and mechanical failures are virtually eliminated.

Features: 

• Not affected by magnetic fields
• Highly dynamic, with an update rate of up to 10 kHz
• Resolution up to 1 µm

Rotary position sensors

Rotary position sensors detect the angular position or rotational movement of a rotating object, such as an axis, shaft, or wheel. They are capable of precisely measuring the angular position or rotational speed.

Single-turn angle sensors vs. multi-turn angle sensors

Single-turn angle sensors measure the absolute angular position within a single revolution (0–360°). After each complete revolution, the output signal repeats; the number of revolutions is not counted.

Multiturn angle sensors also track the number of revolutions, thereby providing an absolute angular position over multiple revolutions. Depending on the design, revolution counting is performed mechanically via a gear train or micromagnetically using GMR (Giant Magnetoresistance) technology, ensuring that the absolute position is retained even without an external power supply.

Technical advantages: 

• High accuracy
• Measuring range: 0° to 360° for single-turn; 0° to 15,840° for multi-turn
• Resistant to dust, moisture, and vibrations
• Fast response time, real-time measurement (potentiometer)
• Low wear to non-contact
• Wide range of applications (automotive, industrial, robotics)

Linear position sensors

Linear position sensors—often linear position transducers in practice as linear position transducers —detect linear motion and form the core of many automation solutions. They continuously measure positions along straight axes and provide precise information on displacement, velocity, and acceleration.

Industrial applications: 

• Presses and punching machines
• Injection Molding and Plastics Processing
• Robotics and Material Handling
• Test benches and materials testing

Absolute vs. Incremental Measurement Systems

Absolute systems encode precise position data and can immediately determine their position without a reference run, even after a power outage. Incremental systems count pulses relative to reference points and often offer higher resolution at a lower cost.

Selecting the optimal position sensor

Selecting sensors requires a systematic evaluation of all relevant parameters. Careful selection at the start of a project helps prevent costly changes and failures later on.

Accuracy requirements: 

• Standard applications: ±1 mm accuracy
• Precision applications: ±10 μm required
• Ultra-precision: ±1 μm or better
• Research Applications: Nanometer Resolution

Determine the measurement range:

• Short stroke 0–25 mm: Compact applications
• Standard stroke 25–250 mm: Typical industrial applications
• Long stroke 250–2000 mm: Large machine axes

Environmental conditions: 

• Standard temperature range: -25 °C to +70 °C
• Temperature range for mobile applications: -40 °C to +125 °C
• Temperature range for high-temperature applications: > +125 °C
• Protection ratings: IP54 to IP69K, depending on requirements
• Chemical resistance: Specific to media and industries
• Functional Safety: PL/SIL

Interfaces: 

• Analog outputs (Current, Voltage, etc.)
• Digital signals (SSI, PWM, SPI, IO-Link, …)
• Fieldbus systems (CANopen, CAN SAE J1939, …)

Installation and Maintenance

Proper installation is crucial for long-term reliability. The mounting must be rigid and vibration-resistant, while also accounting for thermal expansion. The electrical installation requires special attention to electromagnetic compatibility.

Maintenance recommendation:

• Regular visual inspections for damage
• Checking the cable connections
• Functional tests using reference positions
• Calibration according to the manufacturer's specifications

Our services for position sensors

As specialists, we offer a full range of services, from consulting to technical support. Our service begins with a detailed application analysis to develop optimal sensor solutions.

What we offer:

• Requirements Analysis and Expert Consulting
• Simulations
• Development of Custom Solutions
• Flexible manufacturing, from prototypes to mass production
• Support for critical applications

Quality and product certifications:

• ISO 9001:2015 Quality Management
• DIN EN 12067-2 Combustion Systems
• E1 Type Approvals from the KBA

Contact us for technical advice tailored to your needs!