Fiber Optic Sensor Through-beam Switch

A fiber optic through-beam switch detects objects by transmitting a light beam from a separate transmitter to a receiver, triggering a signal when the beam is interrupted.How It Works

A through-beam fiber optic sensor consists of two main components: a transmitter that emits a light beam and a receiver that detects the beam. When an object passes between the transmitter and receiver, it interrupts the light, causing the sensor to change its output state, effectively acting as a switch . Unlike reflective sensors, through-beam sensors are highly reliable for detecting objects regardless of color, surface finish, or material .

Components and Design

Fiber optic sensors include:

• Sensor heads: These are the fiber optic cables or tips that transmit and receive light. They contain no electronics, making them suitable for tight or harsh environments .
• Amplifier unit: This contains the light source and processing electronics, interpreting the received light signal and generating the output . Through-beam sensors can be designed with aluminum sheathing for high-temperature applications (up to 290°C), chemical resistance, and small bending radii for installation in confined spaces .

Applications

Through-beam fiber optic switches are widely used in:

• Industrial automation: Detecting parts on assembly lines or conveyor systems.
• Harsh environments: Areas with high temperatures, chemicals, or limited space where conventional sensors cannot operate .
• Precision detection: Detecting small or transparent objects that are difficult for other sensors to sense .

Advantages

• High reliability: Works with objects of any color or surface finish .
• Long sensing range: Can detect objects over extended distances depending on the model .
• Flexibility: Fiber optic heads can be positioned in tight or hazardous areas while the amplifier remains in a safe location .
• Durability: Resistant to chemicals, heat, and mechanical stress .

Product Examples

• ifm E20753: A fiber optic through-beam sensor with technical data, mounting instructions, and CAD drawings available for industrial integration .
• Keyence FU Series: Offers through-beam sensor heads compatible with amplifiers, suitable for detecting difficult targets in factory automation .
• Balluff Through-beam Sensors: Reliable detection for objects with heavy gloss finishes or challenging surfaces .
• Mouser Electronics: Provides a range of through-beam fiber optic sensors with datasheets and inventory for selection .
• GlobalSpec: Offers high-temperature, chemically resistant through-beam fiber optic proximity sensors with compact designs for limited mounting space . Through-beam fiber optic switches are essential in applications requiring precise, reliable, and flexible object detection, especially in environments where conventional sensors may fail.