What are the differences between photoelectric sensors?

Photoelectric sensors are classified as follows and have the following main features:

Through-beam sensors

In a through-beam sensor, the transmitter and receiver are aligned with each other. The advantage of this solution is that the light reaches the receiver directly, which enables large detection ranges and a high amplification span. These sensors can reliably detect almost any object. The angle of incidence, the surface texture, the color of the object, etc. do not play a role and have no influence on the functional reliability of the sensor.

Retroreflective sensors

The transmitter and receiver are arranged in a housing that makes retroreflective sensors easy to install. Simply attach the reflector on the opposite side and align the sensor with it. The standard version with polarization filter combines the mounting advantages of the retro-reflective sensor with reliable detection at long distances, even with reflective objects. Retro-reflective photoelectric sensors for detecting transparent objects are ideal for the reliable detection of transparent objects.

Diffuse reflection light scanners

Diffuse sensors are very easy to install as only one device needs to be fitted and no reflector is required. These sensors work primarily at short distances and offer optimum switching accuracy and reliable detection of even very small objects. Background suppression sensors only detect a specific area in front of the sensor and ignore all objects outside this area. Background suppression sensors are also insensitive to interfering objects in the background, and even if they are present, they remain extremely accurate.

Photoelectric distance sensors

Photoelectric distance sensors are used when distances to objects need to be measured or monitored, or when their exact position needs to be determined. There is a wide range of output signals. For example, you can choose between analog current and voltage outputs or digital serial interfaces. However, variants with IO-Link are also available for simple and efficient connection to higher-level control systems. There are two basic measuring methods: Triangulation for precise measurement tasks or time-of-flight for area-independent position measurement.

Fiber optic sensors

Sensors and cables with fiber optic cables are a perfect solution for situations where direct mounting is not possible due to lack of space, extreme temperatures and similar factors. The narrow beams of fiber optic sensors are ideal for detecting small objects.

Fork sensors, angle sensors, optical windows

Due to their fast response, these devices are ideal for detecting small objects from a great distance. They are often used for object detection on vibrating and oscillating conveyor systems. Fork light barriers and optical windows are ideal for demanding counting and monitoring tasks, such as detecting free-falling, unattached objects.

Contrast sensors and color sensors

For the In the automation of packaging and printing processes, the detection of print and color plays a decisive role in the coordination of various process steps. Optical contrast sensors are specially designed for these detection tasks.

Light grids

Light grids are ideal for applications where monitoring of larger areas is required. Light grids are easier to mount, install and align, making them preferable to a larger number of individual optical sensors. Applications include width, height and profile control or position-independent object detection.