The WTB4 MultiLine photoelectric sensor from SICK Inc., Minneapolis, MN, uses special optics to create two line-shaped light spots to continuously detect objects with large gaps, such as PCBs, or products are shiny or dark from leading to trailing edge. To activate the output, both light sources must reflect light back to the sensor. Once both light sources have been returned, the sensor will remain active even if one of the beams is not returned. This allows the sensor to detect a range of products that previously caused incorrect detection when using a single-point sensor.
Dual-Line Photoelectric Sensor from SICK