Overview
The Sick WT18-N112 is an infrared photoelectric proximity sensor engineered for background suppression applications in industrial automation. This used unit combines reliable detection performance with straightforward setup, using a potentiometer for simple range adjustment. With a 150 mm sensing range and compact form factor, it delivers consistent object detection while ignoring background interference.
Key Features
- Background suppression — ignores distant surfaces; responds only to objects within programmed range
- Infrared LED light source — robust detection independent of ambient lighting
- Compact rectangular housing — fits tight mounting spaces (17 × 75 × 32.5 mm)
- Potentiometer adjustment — simple dial tuning; no teach-in buttons required
- PNP switching output — standard for most automation controllers
- 2-meter cable included — ready to wire
Technical Specifications
The following specs reflect typical Sick WT18-N112 performance:
- Supply Voltage: 10–30 V DC
- Output Current: ≤ 0.2 A
- Sensing Range: 50–150 mm (object at 90% reflectance)
- Light Type: Infrared LED
- Switching Mode: Light/dark switching
- Response Time: < 700 µs
- Connection: 2-meter cable with color-coded leads
- Housing Material: Plastic (ABS)
- Dimensions (W × H × D): 17 × 75 × 32.5 mm
- Weight: 0.1 kg
- Operating Temperature: –40 to +60 °C
- Storage Temperature: –40 to +75 °C
Typical Applications
- Part presence detection on conveyor lines
- Object counting in packaging and bottling
- Material level sensing without contact
- Slot detection and positioning
- Container fill detection with background rejection
- Machine guarding and safety interlocks
Compatibility & Replacements
Compatible With
- 24 V DC and 12 V DC industrial power supplies
- PLC digital input modules (24 VDC logic)
- Automation controllers from Siemens, Allen-Bradley, Omron, Mitsubishi
- Hard-wired relay circuits with 24 VDC loads
- Standard industrial relay logic panels
Replaces / Drop-In Replacement For
The Sick WT18-N112 is discontinued by the manufacturer. Verify compatibility with your system integrator before ordering. Related Sick background suppression models in the WT18 family may have overlapping applications but different connectors and voltage specifications.
Works With
- Standard PNP (sourcing) input circuits
- 24 VDC relay coil and contactor circuits
- PLC discrete input modules (24 VDC)
- Automation software platforms including TIA Portal (Siemens), Studio 5000 (Rockwell), GX Works (Mitsubishi)
- General-purpose industrial relay and timer circuits
