Double Sheet Sensors

The "double sheet detection" or "double material detection" application originally comes from the printing industry. There, the occurrence of a double sheet must be reliably detected with an extremely short delay in order to avoid time-consuming and cost-intensive system downtimes. In the meantime, however, the range of applications for these devices has expanded considerably: In addition to paper, double sheet sensors or double material sensors can also be used to monitor the passage of plastic films, woods, metals or even highly reflective solar wafers in machines. Likewise, the detection of glued joints or labels can be realized without major effort.

The technical basis of the solution is always a pair of ultrasonic transmitters and receivers that continuously monitor the material flow in a machine by means of ultrasonic pulses. Based on a change in amplitude, the double sheet sensor now detects whether a double layer of material has been fed or whether there is an adhesive spot or label on the material passing through.

State-of-the-art industrial double sheet sensors or double material sensors, such as those manufactured by Pepperl+Fuchs (e.g. devices of type UDC-18GS-*IO-* and UDC(M)-30GS-*IO-*), also offer a number of other advantages in addition to their exceptional robustness and high detection speed: Users can quickly and conveniently select between three predefined threshold settings for different material thicknesses via two sensor inputs or an integrated IO-Link interface. In addition to simplified commissioning or adjustment during operation, the IO-Link interface of these double sheet sensors also opens up new potential for machine analysis and maintenance. Without additional wiring effort, it provides access to all sensor parameters as well as diagnostic and process data. For example, live monitoring of process data can help to check the threshold settings in the double sheet sensor depending on the material currently being run and its specific damping behavior.

If several double sheet sensors are to be used in close proximity to each other for double material control, the built-in automatic synchronization of the devices comes into play. A simple 1-wire connection between up to ten double sheet sensors prevents mutual interference and thus further increases the functional reliability.