Dynamic Reference Probe DRT 25C from Leuze



Innovative technology for reliable detection of objects even with difficult shapes and surfaces - especially for the confectionery and bakery industry

The challenge: On the conveyor belts of packaging machines (HFFS, FS, Thermoform and VFFS) especially in the confectionery and bakery industry, sensors must reliably detect a variety of products and films. In addition, they should continue to operate without setup effort when products are changed.


The dynamic DRT 25C reference probe specializes in the packaging machine application range. It works reliably with flat to spherical products, with transparent to high-gloss films, and with irregular shapes and contours.

Its innovative detection process with unique reference technology and three light spots uses not the product but the conveyor belt as a reference. Thus, the DRT 25C detects any object as a "deviation" from the belt surface. This makes detection independent of product surface characteristics such as color, gloss, and transparency.



  • Reliable detection

Object detection even for difficult shapes and surfaces ensures high machine throughput and avoids downtime.

  • No adjustment work

Easy changeover of products or packaging materials shortens setup times and enables higher production volumes.

  • Quick and easy setup

The sensor is taught automatically using the belt surface and teach button. This requires only one universal mounting position for all objects.

  • Reliable operation

...even when the conveyor belt is dirty and vibrating.

  • IO-Link for easy integration

Additional functions can be easily integrated into the machine control system - e.g. warning message in case of excessive contamination, use of the counter built into the sensor or blocking of the teach button.


Product Features

Three light beams for maximum reliability

Whatever the shape of the confectionery and baked goods and their packaging: with its three light beams, the DRT 25C reliably detects the front edges of the objects, ensuring smooth processes without machine downtimes. Even products with openings, such as cookie rings, are reliably detected as a cohesive part thanks to the wide scanning. This does not require all three light spots to be on the object.


From transparent to high-gloss

Packaging of the most varied colors and transparency are reliably detected by the reference technology as a "deviation" from the tape surface. This means that even machines that process a wide range of different films can be equipped with just one type of sensor.


No setup times when changing products

During initial setup, the tape surface is taught in as a reference by pressing the teach button. After a product change, no adjustment of this setting is necessary because the reference has not changed. In addition, the mounting position and the alignment of the sensor can continue to be used even with a wide variety of objects. This eliminates possible setup times for the sensor when changing products.


Unique CAT technology

The DRT 25C works with the belt surface as a dynamic reference for detecting objects. To do this, the surface properties of the tape are taught in via the teach button. The sensor then detects all objects that do not correspond to the belt surface. Even contamination on the conveyor belt can be compensated for with Contrast Adaptive Teach technology.



Detection of products on conveyors of primary packaging machines



The leading edges of the products on the conveyor belt must be reliably detected for the control of the accumulation section and the sealing bar. The sensor must thereby also reliably detect products with difficult geometries from very flat to high towering to exclude machine downtime due to false detections. The sensor should be easy to set up for all products.


The DRT 25C reliably detects the complete spectrum from small and flat to tall and spherical products - and this even with irregular shapes and contours. This means that machines can be equipped with just one type of sensor, regardless of the application. The 1-button teach function also makes the DRT 25C easy to set up.


Detection of products on conveyors of secondary packaging machines



Packaging made of different materials and with diverse surfaces must be reliably detected from the leading edge for smooth control of the accumulation line. When changing products or packaging films, no setup or adjustment work should be required on the sensor.


The unique technology of the DRT 25C dynamic reference probe uses the tape surface as a reference. This makes detection independent of the surface properties of the materials used, such as color, gloss and transparency. As a result, no setup work is required on the sensor when changing products.


Fast Facts

  • Referenz-Technologie und 3 LED-Lichtflecke 
  • Arbeitsbereich für Förderbandabstände von 50 – 200mm
  • Schaltfrequenz 750Hz, Band-Geschwindigkeiten bis zu 2m/s
  • Bedienknopf (Teach-Taste)
  • IO-Link-Schnittstelle im Dual Channel Prinzip oder SIO-Mode
  • Kompaktes Gehäuse: 15mm x 42,7mm x 30mm
  • Schutzklasse IP67 und IP69K, ECOLAB-Zertifizierung



Data sheet


For more information about our products and services, contact a Schmachtl sales representative. We will be happy to answer any questions you may have.

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