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Rectangular plastic sensor, red LED, M12 connector, potentiometer adjustment

Sick

Sick WL11G-2B2531 Photoelectric Retro-reflective Sensor NPN PNP electrician tool

SKU CH-NB3Q-013YR

Photoelectric retro-reflective sensor detects transparent objects up to 4 m with visible red LED and selectable NPN or PNP output

  • Detects transparent objects with polarised retro-reflective sensing
  • Senses up to 4 m range using visible 640 nm red LED
  • Selectable light or dark switching via L/D control cable
  • Compact 15.6 × 48.5 × 42 mm ABS housing rated IP66 IP67 IP69K
  • Dual NPN and PNP outputs with 100 mA max current

Sick WL11G-2B2531 Retro-reflective Sensor

The Sick WL11G-2B2531 is a photoelectric retro-reflective sensor designed for industrial detection tasks. It uses visible red LED light at 640 nm with autocollimation optics to detect objects up to 4 m away. The rectangular plastic housing measures 15.6 mm by 48.5 mm by 42 mm and weighs 120 g. It offers both NPN and PNP switching outputs with selectable light or dark switching via an L/D control cable.

Verify Voltage and Connector Compatibility

Before ordering, confirm your control system supplies between 10 V DC and 30 V DC with a maximum ripple of 5 Vpp. The sensor draws up to 30 mA and requires a male M12 5-pin connector for wiring. Ensure the mounting location accommodates the 15.6 mm width and 42 mm depth. The IP66, IP67 and IP69K ratings suit harsh environments, but check that the 1.5° dispersion angle and 25 mm light spot at 1.5 m suit your target size.

Ideal for Transparent Object Detection

This sensor suits automation engineers needing reliable detection of transparent materials such as glass or clear film. The 11-turn potentiometer allows precise sensitivity adjustment for low-contrast targets. Builders who require a through-beam or diffuse-mode principle should look elsewhere, as this unit operates only in retro-reflective mode. Applications demanding switching frequencies above 1,500 Hz or response times faster than 330 µs will need a different sensor class.

Highlights

  • Detects transparent objects with polarised retro-reflective sensing
  • Senses up to 4 m range using visible 640 nm red LED
  • Selectable light or dark switching via L/D control cable
  • Compact 15.6 × 48.5 × 42 mm ABS housing rated IP66 IP67 IP69K
  • Dual NPN and PNP outputs with 100 mA max current

Specifications

BrandSICK
ModelSICK WL11G-2B2531

Questions about this item

Does the Sick WL11G-2B2531 sensor include a reflector or M12 cable in the box, or must they be purchased separately?

The sensor has a male M12 5-pin connector; a mating cable and a suitable retro-reflector are not included and must be bought separately.

The specifications list both NPN and PNP outputs — how do I select which one to use?

The unit provides both NPN and PNP switching outputs simultaneously; wiring to the appropriate M12 pin selects the type needed for the controller.

What does the 4 m sensing range mean when the sensor is mounted on a conveyor detecting clear bottles?

With the potentiometer set for transparent-object detection, the sensor reliably switches up to 4 m using a standard reflector, with an 8 % attenuation margin along the beam.

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