Contactless safety sensors

Non-contact safety sensors are devices that are used in various applications to ensure the safety of people and prevent accidents. In contrast to conventional safety sensors, which are activated by touch, non-contact sensors detect the approach or presence of a person without direct contact.

There are various types of non-contact safety sensors, including optical sensors, capacitive sensors, magnetic sensors and infrared sensors. Each sensor uses a specific technology to detect the presence of a person.

Optical sensors, for example, use light beams to create an invisible light barrier. If a person breaks through the light beam, the signal is sent to a control unit, which can then take appropriate action to ensure safety.

Capacitive sensors, on the other hand, detect the change in the electric field when a person comes close to the sensor. The electric field is normally built up between two electrodes. When a person approaches, the electric field changes and the sensor detects this change.

Magnetic sensors use magnetic fields to detect the presence of a person. If a person approaches the sensor, the magnetic field is disturbed and the sensor detects this disturbance.

Infrared sensors use infrared radiation to detect the presence of a person. Infrared rays are emitted and when a person comes close to the sensor, part of the radiation is reflected or absorbed. The sensor recognizes this change and reacts accordingly.

Non-contact safety sensors are widely used in various applications, such as industrial machinery, elevators, automatic doors, robots and many other areas where the safety of people is of great importance.

Non-contact safety sensors offer a number of advantages over conventional safety systems:

1. No physical contact: Non-contact sensors make it possible to detect people or objects without the need for physical contact. This minimizes the risk of injury or damage due to contact with safety devices.

2. High reliability: Non-contact sensors work with modern technology such as infrared, ultrasound or laser technology. As a result, they are less susceptible to faults or malfunctions compared to conventional mechanical safety systems.

3. Flexibility: Non-contact safety sensors can be used at different locations and in different environments. They are adaptable and can be integrated into machines, vehicles or robots, for example.

4. Fast response time: Non-contact sensors detect movements or approaches in real time and react immediately. This means that potential hazards can be identified quickly and appropriate measures taken to prevent accidents.

5. Simple integration: Non-contact sensors can be easily integrated into existing security systems. They can be used together with other sensors, alarm systems or monitoring systems to provide a comprehensive security solution.

6. High accuracy: Non-contact sensors provide precise measurements and detections. This enables them to precisely determine the distance to objects, for example, or to precisely detect the position of people or machines.

7. Cost efficiency: Although non-contact sensors often have a higher initial cost, they can be more cost-effective in the long term. They reduce the risk of accidents or damage, which leads to lower repair and maintenance costs.

Overall, non-contact safety sensors offer improved safety, flexibility and efficiency compared to conventional safety systems. They are an important component in modern safety solutions and help to prevent accidents at work and ensure the safety of people and machines.

There are different types of non-contact safety sensors that are used depending on the area of application. Here are some examples:

1. Light barriers: These sensors consist of a light source and a receiver, which are positioned opposite each other. If an object interrupts the light beam, a signal is triggered. Light barriers are often used in areas where a protective field must be generated to prevent access to a danger zone.

2. Radar and ultrasonic sensors: These sensors use electromagnetic or sound waves to detect the position and movement of objects. They are often used in areas where non-contact monitoring is required, such as in automated factories or in vehicle technology.

3. Capacitive sensors: These sensors detect changes in the electrical capacitance when an object comes close to the sensor. They are often used in applications where it is important to monitor the presence or movement of people or objects, such as in automation technology or mechanical engineering.

4. Infrared sensors: These sensors use infrared radiation to detect the position or movement of objects. They are often used in safety technology to monitor access to certain areas or to prevent collisions, e.g. in automated gates or elevators.

5. Magnetic sensors: These sensors use magnetic fields to detect the presence or movement of objects. They are often used in the automotive industry, for example for detecting vehicles in parking garages or for monitoring doors and windows.

This list is not exhaustive, as there are many other types of non-contact safety sensors that can be used depending on the area of application.

Non-contact safety sensors can help prevent accidents and injuries by monitoring the environment and detecting potentially dangerous situations. Here are some ways you can contribute to this:

1. Recognition of persons: Sensors can detect people in the vicinity of machines or vehicles and monitor their presence. If a person gets too close, the sensors can trigger a warning signal to alert the operator or the person and protect them from a possible collision.

2. Obstacle detection: Sensors can detect obstacles or objects that could hinder the normal operation of machines or vehicles. For example, you can detect whether an object is in an area where it should not be and stop the machine to prevent a collision or damage.

3. Monitoring of danger zones: Sensors can monitor special danger zones where there is an increased risk of injury, e.g. rotating machine parts or moving parts. If a person gets into this zone, the sensors can react immediately and stop the machine to prevent injury.

4. Speed monitoring: Sensors can monitor the speed of machines or vehicles and ensure that they remain within safe limits. If a machine is moving too fast or out of control, the sensors can detect this and take appropriate action to prevent accidents.

5. Alerting in the event of deviations: Sensors can also help to detect and alarm deviations from normal operating parameters. This may include, for example, temperature changes, pressure drops or other anomalies that could indicate potential hazards.

Overall, non-contact safety sensors can help improve safety in work environments by protecting operators and people from dangerous situations and preventing potential accidents and injuries.

Various technologies are used in non-contact safety sensors to ensure their performance. Here are some of the most common technologies:

1. Infrared (IR): IR sensors use infrared rays to detect the position and movement of objects. They can measure distances and are able to detect movement. Their performance can be influenced by factors such as backlighting and reflection from surfaces.

2. Ultrasound: Ultrasonic sensors use sound waves with a frequency above the human hearing range to measure distances and movements. You can also recognize obstacles. The performance of ultrasonic sensors can be influenced by ambient noise and sound reflections.

3. Capacitive: Capacitive sensors measure changes in electrical capacitance when an object comes close to the sensor. They can detect both distant and touchable objects. The performance of capacitive sensors can be influenced by the material and surface of the detected object.

4. Magnetic: Magnetic sensors use magnetic fields to detect objects. They can detect both ferromagnetic and non-ferromagnetic materials. The performance of magnetic sensors can be influenced by external magnetic fields and distance measurement.

5. Laser scanner: Laser scanners use laser beams to measure the distances and positions of objects. They can also monitor areas and detect obstacles. The performance of laser scanners can be influenced by ambient light and reflections.

The performance of these technologies can be influenced by various factors, such as environmental conditions (temperature, humidity, light), reflections from surfaces, interference from other electronic devices, interference with other sensors and the accuracy of the measurements. It is important to take these factors into account when selecting and installing the safety sensors to ensure reliable operation.

Various norms and standards apply to non-contact safety sensors to ensure their functionality and reliability. A widely used standard is EN ISO 13849-1, which deals with the safety-related parts of control systems. Among other things, the performance level (PL) is defined here, which indicates how secure a system is.

Another important standard is IEC 61496, which was developed specifically for electro-sensitive protective equipment. This standard defines various types of safety sensors, such as light barriers or safety laser scanners, and specifies requirements for their functionality and reliability.

To check compliance with these norms and standards, non-contact safety sensors are usually subjected to extensive tests. Various criteria are tested, such as the response time of the sensor, the detection ranges and the reliability of the safety functions. The tests can be carried out both in the laboratory and in real application scenarios.

Once the tests have been successfully completed, the manufacturer can apply for certification. This is issued by independent testing organizations or certification bodies that check and certify compliance with the norms and standards. Well-known certification bodies in the field of safety technology include TÜV and UL. The certification serves as proof that the sensor complies with the applicable norms and standards and can therefore be used safely.

Non-contact safety sensors can be integrated into existing safety systems by connecting them to the existing infrastructure. Here are some steps that should be followed:

1. System analysis: Examine the existing safety system and identify the areas where non-contact safety sensors are required. Also determine the requirements and specifications for the sensors.

2. Selection of sensors: Select non-contact safety sensors that meet the requirements of the system. Consider factors such as range, sensitivity, environmental factors and specific safety standards.

3. Installation: Place the sensors in the intended locations and ensure that they are properly installed. Follow the manufacturer's instructions and observe any specific requirements.

4. Cabling: Connect the sensors to the existing security system. Depending on the specific requirements, these can be cable connections or wireless connections. Ensure that the cabling is properly routed and insulated to minimize interference.

5. Configuration and calibration: Include the sensors in the security system and configure them according to the requirements. Calibrate them according to the specific conditions on site to ensure optimum performance.

6. Integration tests: Carry out comprehensive tests to ensure that the sensors function properly and work seamlessly with the existing security system. Check the response times, the accuracy of the detection and the alarm functions.

7. Training and maintenance: Train safety personnel in the use of the non-contact sensors and inform them about possible malfunctions and maintenance requirements. Ensure that regular maintenance work is carried out to maintain the functionality of the sensors.

Through these steps, non-contact security sensors can be successfully integrated into existing security systems to improve the protection and security of people and property.