Sick WL12-3P2451 Photoelectric Sensor
Sick WL12-3P2451 is a retro-reflective photoelectric sensor with 0–2 m sensing range, 2 mm light spot, PNP output operation support. This Sick photoelectric sensor from the W12 series uses autocollimation optics, visible red LED at 640 nm, polarisation filters, and focused optics for detecting small objects, operating on 10–30 V DC with light/dark switching, ≤330 µs response time, IP66/IP67/IP69K enclosure ratings, and an M12 4-pin connector.
| Brand | Sick |
| Product Type | Photolectric Sensor |
| Model Number | WL12-3P2451 |
Sick WL12-3P2451 Photoelectric Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Functional principle | Photoelectric retro-reflective sensor |
| Functional principle detail | Autocollimation |
| Sensing range max. | 0 m ... 2 m |
| Sensing range | 0 m ... 1.3 m |
| Polarisation filters | Yes |
| Light source | LED |
| Type of light | Visible red light |
| Light spot size (distance) | Ø 2 mm (90 mm) |
| Wave length | 640 nm |
| Adjustment | Potentiometer, 5 turns |
| Angle of dispersion | Approx. 5° |
| Special applications | Detecting small objects |
| Items supplied | 2 x clamps BEF-KH-W12, incl. screws |
| Supply voltage UB | 10 V DC ... 30 V DC |
| Ripple | < 5 Vpp |
| Current consumption | 30 mA |
| Protection class | III |
| Digital Output type | PNP |
| Switching mode | Light/dark switching |
| Signal voltage PNP HIGH/LOW | > Uv - 2,5 V / ca. 0 V |
| Output current Imax. | ≤ 100 mA |
| Response time | ≤ 330 µs 4) |
| Switching frequency | 1,500 Hz 5) |
| Output function | Complementary |
| Special feature | Focused optics |
| Housing | Rectangular |
| Dimensions (W x H x D) | 15.6 mm x 48.5 mm x 42 mm |
| Connection | Male connector M12, 4-pin |
| Housing material | Metal |
| Front screen material | Plastic, PMMA |
| Enclosure rating | IP66, IP67, IP69K |
| Ambient operating temperature | –40 °C ... +60 °C |
| Ambient temperature, storage | –40 °C ... +75 °C |
| Weight | 120 g |
The WL12-3P2451 Sick 2 mm Light Spot Retro-reflective Sensor is a rectangular photoelectric sensor designed for precise object detection in industrial automation. It uses a retro-reflective autocollimation principle with a focused 2 mm light spot and a maximum sensing range of 2 m. The device provides a PNP digital output, operates on 10–30 V DC, and belongs to the Sick W12 series, which is widely applied in automation systems requiring stable optical sensing.
In industrial environments, the WL12-3P2451 Sick 2 mm Light Spot Retro-reflective Sensor is commonly used on conveyors, packaging machines, automated assembly lines, and small-part detection stations. The narrow light spot allows reliable detection of small or closely spaced objects, while the retro-reflective principle ensures consistent switching behavior. Its high switching frequency supports fast-moving processes, and the metal housing with high ingress protection enables dependable operation in demanding automation conditions.
The WL12-3P2451 from Sick combines defined optical performance, controlled response time, and robust mechanical design for long-term industrial use. With features such as focused optics, PNP output, and wide temperature tolerance, it fits standard automation control architectures. As part of the W12 series, this Sick photoelectric sensor aligns with established industrial automation requirements, offering consistent detection behavior and electrical compatibility expected in professional industrial installations.

