Two photoelectric sensors in one housing that combine logic evaluation intelligently with one another – the MultiLine sensor proves to be a high-end sensor in difficult situations for detecting flat or textured objects.
The special characteristic of the MultiLine sensor is the two parallel light lines, i.e. the compact W4 housing accommodates not one but two photoelectric sensors operating simultaneously. And “two eyes” detect better, particularly when objects, such as printed circuit boards have gaps or openings or if – in the case of blister packs or soup packets – they are exceedingly flat.
The problem: one object, one light spot but no continuous and reliable signal
With respect to objects with gaps, using conventional photoelectric sensors involves the risk that the light and thus the reflection to the sensor may disappear there. The consequence is that the sensor switches off even though the object is still present. A similar phenomenon can be observed in the case of flat objects with reflective, curved, and transparent areas. Here, too, the light may disappear for a short time and switch off the photoelectric sensor, even though, e.g., a flat, reflective package such as a soup packet may still be located on the conveyor belt.
Double detection prevents false switches
With the MultiLine sensor, these problems are now a thing of the past. When an item moves into the scanning range of the sensor, it switches on if the two lines have detected the object. The signal will be active until both light lines no longer signal an object. If in the meantime one of the light lines goes missing, e.g. in a gap of the printed circuit board or through deflection on the surface of the package, the other line maintains the signal.
In this way, critical structured objects remain visible to the sensor and the machine control at any time – false switching is eliminated effectively. The first users are enthusiastic about the MultiLine sensor: “A compact sensor with top detection reliability for applications that would otherwise have to be solved using more elaborate camera technology,” is their assessment.
Where conventional photoelectric sensors get out, it comes in: the MultiLine sensor from SICK.