SICK WTB9-3N2461 Photoelectric Through-Beam Sensor

The SICK WTB9-3N2461 is a compact photoelectric proximity sensor with background suppression, offering a 20–350 mm sensing range in a 12.2 mm wide, 52.2 mm tall, 23.6 mm deep rectangular housing. It mounts via an M3 hole and uses a PinPoint LED at 650 nm to form a small light spot of about 4.5 mm at 75 mm, with a 5-turn potentiometer for precise sensitivity adjustment. The device provides an NPN switching output and supports light/dark switching to suit different detection tasks. Target reflectivity of 90% (DIN 5033) and 6% reflectivity are used in its performance specifications, indicating how it responds to standard white references and darker objects. The WTB9-3N2461 is rated for up to 100,000 hours of service at TA = +25 °C and is designed for rugged industrial use, making it appropriate for applications such as presence/absence sensing on production lines and packaging automation. Typical catalog configurations show a 4-pin M12 electrical connection and a supply range up to 30 V DC.