Reliable detection of shrink-wrapped packages

The six-pack is practical for conveniently transporting beverage bottles or cans. In the packaging process, this film-wrapped package does, however, prove to be somewhat demanding as different object heights require detection from above. This can be challenging with various object properties, which range from metallic to colorful to transparent. Our DRT25C.R dynamic reference diffuse sensor offers a simple solution here. Thanks to its increased operating range of 450 mm, it can easily be taught to the conveyor and uses it as a reference. As a result, detection is independent of object. And, above all, reliable: regardless of whether six-pack, eight-pack or multipack.

Advantages for you

  • Reliable detection of film-wrapped packages of all types, regardless of whether six-packs, eight-packs or multipacks or whether transparent or printed film
  • Thanks to its increased operating range of 450 mm, the sensor can easily be taught to the conveyor from above
  • Adaptation to the application by means of two different teach levels
  • Reliable operation even if the conveyor belt is soiled or vibrating
  • For high machine throughput and for avoiding downtime
  • Innovative CAT technology: The conveyor serves as a reference and makes detection independent of object
  • Only one mounting position for all objects
  • No adjustment of the sensor is needed when products or packaging materials are changed. Shorter setup times result in higher production volumes
  • IO-Link for easy integration of additional functions in the machine control, such as warning message in case of excessive contamination, use of the counter built into the sensor, or locking of the teach button



In a filling system, beverages are filled in bottles and cans and shrink-wrapped with film to form packages. The different beverage packages vary in shape and have a height between 80 and 400 mm. They must be detected on a roller conveyor by a sensor. In spite of different types of packages with transparent film or with various types of printing on the film, the sensor must neither detect a given package more than once nor detect incorrectly and must reliably identify the gaps between two packages. In some cases the packages contain cardboard trays.


The unique technology of the new DRT25C.R unit pack sensor uses the conveyor belt surface as the point of reference.
As a result, it reliably detects the entire range of package types regardless of whether they are shrink-wrapped with transparent, brightly printed or metallic film. This means that roller conveyors or link conveyors can be fitted with a single sensor regardless of the application. When changing products, no setup work is required on the sensor. The adjustment is performed conveniently using a teach button.


to the list of articles DRT25C.R 


The flexible sensor

Beverage packages with different colors and transparency are reliably detected as a 'deviation' from the conveyor belt surface due to the reference technology. The sensor is thus able to detect any package – regardless of whether the film is transparent, brightly printed or metallic.

Innovative CAT technology

The DRT 25C.R works with the conveyor belt surface as a dynamic reference for the detection of objects. With this method, the surface characteristics of the conveyor belt are taught in via the teach button. The sensor will then detect all objects that do not correspond to the conveyor belt surface. The DRT 25C thereby functions independent of object, making it more stable than classic diffuse reflection sensors. Even contamination on the conveyor belt can be compensated with the Contrast Adaptive Teach technology.

No setup time when changing products

When performing the initial setup, the conveyor belt surface is taught in as a point of reference with the teach button. After a product changeover, it is not necessary to adjust this setting, as the point of reference remains the same. In addition, the mounting position and the alignment of the sensor itself can be continuously used for the widest variety of objects. This means that no setup effort is required for the sensor when changing products.

Two teach levels

With the robust and sensitive teach function, two different teach levels are available.
The robust teach function, accessed by pressing the button for 2 – 7 seconds, is selected for soiled roller chains or for roller chains with very irregular elements.
The sensitive teach function, accessed by pressing the button for 7 – 12 seconds, is used with highly transparent packages.

Technical properties

Specification Leuze DRT25C.R
Operating range Max. 450 mm (to roller conveyor)
Minimum object height 80 mm
Switching frequency 300 Hz
Temperature -10 to 50 °C
IO-Link Yes
Buttons 1
Detection direction Onto conveyor belt from above