Sick Sensor WTB9L-3N2461

Main Product Series – Function & Application Comparison

Typical Applications & Industries:
✓ Packaging line object detection ✓ Automotive assembly verification ✓ Pharmaceutical blister pack inspection
✓ Food & beverage washdown environments ✓ Electronics manufacturing ✓ Material handling & conveyor systems

Detailed Description – SICK WTB Series Photoelectric Sensors

1. WTB12-3 Series – Rugged Metal Housing for Harsh Environments

The WTB12-3 is part of SICK’s W12 metal sensor family, designed for demanding industrial applications where durability is critical .

Key Features:

• ✓ Zinc die-cast metal housing – withstands high-pressure washdowns, chemicals, lubricants, and mechanical shock 

• ✓ High protection rating – IP66, IP67, IP69K certified for food/pharma washdown environments 

• ✓ PinPoint LED technology – bright, small, precise light spot for easy alignment 

• ✓ Background suppression – ignores stray reflections from machine surfaces behind the target 

• ✓ IO-Link connectivity – remote configuration, real-time diagnostics, predictive maintenance alerts 

Sensing range: Up to 600mm with background suppression 

Industry applications: Packaging lines, automotive assembly, pharmaceutical manufacturing, food processing 

Example models: WTB12-3P2441S59, WTB12-3P2413, WTB12-3N2411 

2. WTB4-3 Series – Ultra-Compact for Tight Spaces

The WTB4-3 is a miniature photoelectric sensor ideal for applications with limited mounting space .

Key Features:

• ✓ Ultra-compact design – fits into tight machine cavities and small automation cells

• ✓ PinPoint LED – visible red light for simplified alignment

• ✓ Background suppression – reliable detection regardless of target color or material

• ✓ Multiple connection options – M8 connectors or pre-wired cables

Sensing range: 3mm to 250mm depending on model 

Ideal for: Electronics assembly, small parts detection, cleanroom environments, precision positioning

Example models: WTB4-3P3261S51, WTB4-3P2261S44, WTB4-3P2100S78 

3. WTB9 Series – Compact with VISTAL® Housing

The WTB9 combines a compact form factor with a rugged VISTAL® housing – a high-strength polymer that resists mechanical stress and chemicals .

Key Features:

• ✓ VISTAL® housing – durable, lightweight, corrosion-resistant

• ✓ PinPoint LED or laser versions – choose based on precision requirements

• ✓ SIRIC® technology – suppresses optical and electromagnetic interference 

• ✓ Best-in-class background suppression – detects objects close to reflective backgrounds 

Sensing range: Up to 800mm for proximity models 

Ideal for: Small object detection, detection through narrow openings, protrusion/misalignment checks

Example model: WTB9L-3P2291 (laser version) 

4. WTB15 Series – High-Performance with Flexible Mounting

The WTB15 series features an M18 front mount design, allowing flush mounting with a snap ring that prevents disruption of material flow on conveyor systems .

Key Features:

• ✓ OES3 technology – 3rd generation custom ASIC for exceptional background suppression 

• ✓ Flexible mounting – M18 front mount or side mount with through holes

• ✓ PinPoint LED – visible red light spot

• ✓ High immunity to ambient light – stable operation in challenging lighting conditions 

Sensing range: 4mm to 200mm 

Ideal for: Conveyor systems, material handling, multi-colored or shiny object detection

Example models: WTB15-P2430S96, WTB15-N2431, WTB15-P1131 

5. WTB8 Series – High-Speed Miniature Sensor

The WTB8 is a miniature photoelectric sensor designed for high-speed applications with switching frequencies up to 2 kHz .

Key Features:

• ✓ High switching frequency – up to 2,000 Hz for fast production lines 

• ✓ Miniature housing – M3 threaded mounting holes for secure installation

• ✓ Background suppression – precise close-range detection

• ✓ Stainless steel bracket included – BEF-W100-A delivered with sensor 

Sensing range: Close-range applications

Ideal for: High-speed counting, small automation cells, fast packaging lines

Key Technology Features Across WTB Series

PinPoint LED Technology

SICK’s PinPoint LED produces a bright, small, and precise light spot that is highly visible. This simplifies sensor alignment during installation and ensures reliable detection of small or poorly reflective objects .

Background Suppression

All WTB sensors feature background suppression technology. The sensor detects objects within a defined sensing range while ignoring reflections from machine surfaces or conveyors behind the target . This prevents false triggering and ensures stable operation.

BluePilot Alignment (W12 Series)

The W12 series includes BluePilot – a blue LED alignment indicator that provides real-time visual feedback of signal strength, enabling quick, tool-free positioning .

ApplicationSelect (W12 Series)

Engineers can choose from predefined operating modes optimized for dark, reflective, or irregular targets without swapping hardware .

IO-Link Integration (Select Models)

IO-Link-enabled WTB sensors provide :

• ✓ Remote configuration – adjust settings from PLC or PC

• ✓ Real-time diagnostics – monitor signal strength, alignment, contamination

• ✓ Predictive maintenance – identify issues before production stops

• ✓ Parameter cloning – copy settings to multiple devices

• ✓ Seamless Industry 4.0 integration

Selection Guide – Understanding the Naming Convention (SICK WTB Series)

SICK WTB part numbers follow a structured logic. Understanding the coding helps rapid selection.

Example: WTB12-3P2441S59

Model decoder examples:

Housing series reference: