BALLUFF-Leuze has released ultrasonic fork sensors that can detect transparent, shiny and metallic labels at high transport speeds. The system is also insensitive to environmental influences, providing good 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 GSU 06 ultrasound label fork sensor is designed to cope with transport speeds of up to 120m/min and is able to detect labels just 2mm in width, whether they are straight, round or diamond-shaped. The smallest possible reliably detectable gap between labels is 2mm.
It is capable of parameterisation 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 fitted with both a PNP and an NPN output for optimum adjustment to different control systems.