Wide application range for fork sensors with ultrasound

Fork sensors are used for detecting new types of packaging and labelling materials. They work using a variety of physical measurement methods ranging from mechanical through optical and capacitative methods through to ultrasound. Leuze electronic was the first company in the world to develop ultrasound as a detection method in conjunction with fork sensors.

The major benefit of the ultrasound principle over other methods is that alongside paper labels it is able to detect transparent, shiny and even metallized labels with absolute precision – and at high transport speeds. As this method is also highly insensitive to environmental influences, it also offers extremely good operating reliability.
Detection takes place by the emission of ultrasonic waves from an integrated transmitter in the lower shank of the form sensor. The receiver in the upper shank receives two signals, a high signal from the backing tape and, because of the greater attenuation, a significantly lower one from the backing tape plus label. This allows the start and end of the label to be determined with a high degree of precision. The new ultrasound label fork sensor GSU 06 is designed to cope with transport speeds of up to 120 m/min and is even able to detect labels just two millimetres in width – no matter whether they are straight, round or diamond-shaped. The smallest possible reliably detectable gap between labels is also two millimetres.

This ultrasound label fork sensor is not only the smallest device on the market, it also offers users an additional highlight: parameterization using teach-in, which can be actuated either by pressing a button at the sensor itself, or by means of remote calibration over the control line.

Each sensor is also fitted with both a PNP and an NPN output for optimum adjustment to different control systems.