Photoelectric Sensors
SICK WT12L-2P140S03 Photoelectric sensor
SICK WT12L-2P140S03 background suppression photoelectric sensor, PNP. Fixed switching point for dark targets in front of bright machine backgrounds.
Overview
The SICK WT12L-2P140S03 is a diffuse photoelectric sensor with background suppression in the W12 housing family. The L variant evaluates the distance of the returned light, so it switches at a fixed point and ignores objects behind it. This makes it the preferred choice where cartons or parts pass in front of machine frames, guides or shiny guard walls.
How It Works
A position-sensitive receiver determines where the reflected light lands. Light from the target distance triggers the output, light from farther surfaces does not. The switching point is therefore set by distance, not by brightness, so dark and light objects are detected at the same position.
Key Features
- Fixed switching point independent of object color and reflectivity
- Background objects beyond the switching point are suppressed
- Compact W12 housing with straightforward one-sided mounting
- Suitable for dark targets in front of bright backgrounds
- Stable behavior on fast-moving lines thanks to short response times
- PNP switching output for standard control systems
Typical Applications
- Detection of dark boxes on conveyors in front of bright machine walls
- Part presence in fixtures where metal parts sit behind the target
- Reliable switching on mixed-color product streams
- End-of-arm verification where grippers and frames are nearby
- Height and stack monitoring with a defined background
Specifications
Attribute | Value |
|---|---|
Model | SICK WT12L-2P140S03 |
Detection principle | Diffuse photoelectric with background suppression |
Housing family | W12 compact rectangular |
Output type | PNP switching output |
Installation and Setup Notes
Set the switching distance with the real target in position, then verify that the nearest background surface is outside the suppressed zone. Because suppression is distance-based, mounting near the background at a similar distance should be avoided. Check the light spot position during commissioning to ensure it stays on the target across its travel.
Frequently Asked Questions
How is the WT12L different from a standard WTB12 diffuse sensor?
The WT12L suppresses the background by distance evaluation, while the standard WTB12 switches on reflected light volume. Use the L variant whenever the background must not influence switching.
Can it distinguish a box from the wall directly behind it?
Yes, as long as the box is inside the switching distance and the wall is beyond it; both must not share the same distance.
Does target color matter?
No, the switching point depends on distance, so black and white objects are detected at the same position.
Related Photoelectric Sensors
For laser time-of-flight detection with longer suppression ranges, see the SICK WTT12L-B2542. For the G6 background-suppression family, see the SICK GTB6-N1212.
