Double sheet control

Doppelbogenkontrolle im Druck

Double sheet control in printing – reliably guaranteed

Double-sheet control focuses on ensuring that only one printed sheet at a time is picked up by the machine in printing plants during the printing process. This must be reliably assured, as it avoids unnecessary waste material. And this is undoubtedly an important factor in allowing print shops to work smoothly, efficiently and, above all, economically.

Print sheet control – precise, in milliseconds fast

The challenge with print sheet inspection is not just the speed at which it has to be carried out – with high repetition rates. The measurement must also be able to deal optimally with different papers as substrates. In any case, it is important to be able to ensure beyond doubt and in minimal time that only one printed sheet actually goes into the machine and not two or even more. High-precision ultrasonic sensors are used here, whose transducers work reliably and at top speed. The highlight: handling is completely simple – without training times.

Wandler für Windmessung Ultraschall

This is how the sensor insert looks in print

Typically, two opposing ultrasonic transducers work in transmitter and receiver mode during double sheet detection. The intensity of the transmitted signal is used to detect possible double or multiple layers. To prevent crosstalk* during measurement, we recommend arranging the SECO sensor ultrasonic transducers in an array design. Our ultrasonic experts will be happy to advise you on this.

* What does “crosstalk” mean? When measuring with several sensors, it can happen that the signal from one sensor jumps over to neighboring sensors, resulting in incorrect measured values. This can be particularly problematic in optical or acoustic sensor systems. The array design described prevents this undesirable effect.

The function of sensors in double sheet control

When used in printed sheet inspection, a transmitting and a receiving ultrasonic transducer face each other. Papers in particular, but also foils or even thin sheets, are “sonicated” by the technology with the resulting vibrations. During this process, the emitting transducer emits a short, high-frequency pulse of sound, which then travels through the air and the material at the speed of sound. As soon as the signal reaches the receiver on the other side, the ultrasonic sensor recognizes the possible additional material layer from the intensity of the signal – i.e. the double (or multiple) printed sheet. This is very easy to use in practice and reliable even in difficult ambient conditions.

The following requirements apply to the transducers as part of the double sheet control:

  • High signal voltage for transmission measurement
  • Low crosstalk thanks to array design and small beam width
  • Fast measurements thanks to high repetition rate
  • Application examples: Offset printing, cash terminals, desktop scanners, label recognition

Feel free to contact us if you are creating sensors for double sheet control. We can provide you with all-round advice on ultrasonic transducers in order to raise the quality of your sensors to the highest level. We plan, develop and manufacture ultrasonic transducers based on your individual requirements or those of your customers. You can reach us by e-mail at or personally on the phone at +49 (0)9561 869141

Thematic background:

The double sheet sensor uses ultrasound to detect sheets of paper, film or even thin metal. The sheets can therefore be made of different materials that are sonicated through, and we will be happy to explain in more detail how thick or thin they are. Ultrasonic double sheet detection using ultrasonic sensors is a highly reliable measuring method for avoiding double sheets. Detection takes place directly on or in the machines. Depending on the measuring task, you can use our tried-and-tested standard products or we can work with you to develop a customized ultrasonic transducer for special challenges.