Reflex sensors for hygienic applications in the pharmaceutical industry

Pharmaceutical production places high demands on precision, hygiene and process reliability. Sensor solutions must not only work reliably, but also meet the special cleaning and hygiene standards. Reflex sensors with different operating principles offer a robust basis for precisely detecting objects even under difficult conditions.

Reflex sensor under a transparent turntable monitors the labeling station
Presence and path control on the rotating applicator.

Functional principles of reflex sensors

Reflex sensors integrate the emitter and receiver in one housing. Different measuring principles are used depending on the design:

  • With triangulation, the position of the reflected light spot is evaluated. This method enables high accuracy at short working distances and is suitable for small objects or materials of different colors.
  • Time-of-flight sensors measure the transit time of light pulses. This makes it possible to achieve greater ranges and ensure material-independent detection even on shiny or transparent surfaces.
  • Energetic Reflex Sensors work on the basis of the intensity of the reflected light. They are mainly used for simple presence checks and for clear color or material contrasts.

Sensors for hygienic environments

Miniature sensors in stainless steel housing with a high degree of protection and cleaning resistance are available for applications in regulated production environments. The format is compact, the material meets common hygiene standards and the sensors are resistant to high-pressure and hot water cleaning. This makes them suitable for use in areas where aggressive cleaning processes are regularly carried out.

Applications in pharmaceutical production

Typical applications in the pharmaceutical industry include the inspection of cartons and magazines, the monitoring of magazine fill levels and the detection of glossy or colored packaging. Here, reflex sensors with background suppression or retro-reflex sensors are often used, which deliver stable results even with different colors and reflective surfaces. Another field of application is the monitoring of transparent materials, such as film rolls or blister packs. Miniature sensors with blue light and background suppression enable reliable presence checks and fill level monitoring.

By integrating IO-Link, the sensors can be incorporated into digitized systems. This enables simple parameterization, the transmission of process data and continuous condition monitoring.

Reflex sensor checks a transparent film/label web on the large deflection wheel
Reliable detection of transparent and reflective materials.

Reflex sensor with red light spot detects products at the outlet of an inclined infeed conveyor
Precise triggering for counting, separation and ejection.
Several reflex sensors and positioning sensors monitor conveyor belts, feeders and grippers in a packaging machine
Monitoring of feed, position and stowage points.

Selection criteria for the right technology

The choice of a suitable reflex sensor depends on the general conditions of the application. Triangulation sensors offer advantages for short distances and small objects. ToF sensors are suitable when larger distances need to be bridged or different material properties need to be reliably detected. Energetic Reflex Sensors can be used for simple presence checks or clear material differences.

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Picture of Max Mustermann

Max Mustermann

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