SICK 1041390 WL11G-2B2531 PNP/NPN Clear-Object Retro-Reflective Sensor

Technical Overview

The SICK WL11G-2B2531 is a retro-reflective photoelectric sensor for transparent-object detection with PNP and NPN outputs. Coaxial autocollimation optics allow operation without a reflector minimum distance, with a specified 0–4 m sensing range using PL80A. Its 640 nm visible red LED forms a 25 mm spot at 1.5 m, while an eleven-turn potentiometer adjusts reception. An L/D control cable selects light or dark switching, and the specified beam attenuation threshold is greater than 8%. Response of no more than 330 µs, 1,500 Hz switching, an M12 five-pin plug and IP66/IP67/IP69K ABS housing support machine integration.

PNP/NPN retro-reflective sensor with 0–4 m with PL80A reflector, transparent-object detection and Plug M12, 5-pin.

Key Features

Transparent-object retro-reflective sensing

Coaxial autocollimation; no reflector minimum distance

0–4 m sensing and maximum range with PL80A

640 nm red LED; Ø25 mm spot at 1.5 m

Eleven-turn sensitivity potentiometer

PNP and NPN outputs; L/D control selects switching logic

Response ≤330 µs; 1,500 Hz switching

Beam attenuation >8%

M12 five-pin plug; 10–30 V DC supply

IP66/IP67/IP69K ABS housing; PMMA optics

Technical Specification Matrix

Parameter	Value
Functional principle	Photoelectric retro-reflective sensor
Sensing range	0–4 m with PL80A reflector
Maximum sensing range	0–4 m with PL80A reflector
Switching output	PNP/NPN
Optical design	Autocollimation/coaxial optics; no reflector minimum distance
Special feature	Detecting transparent objects
Light source	LED, visible red light
Wavelength	640 nm
Light spot size	Ø25 mm at 1.5 m
Adjustment	Potentiometer, 11 turns
Switching mode	Light/dark switching, selectable via L/D control cable
Power supply	10–30 V DC; short-circuit-protected network max. 8 A
Residual ripple	<5 Vpp; remain within supply tolerances
Current consumption	30 mA without load
Output current	≤100 mA
Response time	≤330 µs with resistive load
Switching frequency	1,500 Hz at light/dark ratio 1:1
Beam attenuation	>8%
Connection	Plug M12, 5-pin
Circuit protection	Supply reverse-polarity protection, interference suppression and output overcurrent/short-circuit protection
Protection class	III
Housing material	ABS plastic
Optics material	PMMA plastic
IP rating	IP66, IP67 and IP69K
Operating temperature	−30 to +60 °C
Storage temperature	−40 to +75 °C
MTTFD	823 years
Diagnostic coverage DCavg	0%
UL file	NRKH.E181493 and NRKH7.E181493
Dimensions L x W x H (cm)	4.2 x 1.56 x 4.85
Physical Weight (kg)	0.12

Parameter

Value

Functional principle

Photoelectric retro-reflective sensor

Sensing range

0–4 m with PL80A reflector

Maximum sensing range

0–4 m with PL80A reflector

Switching output

PNP/NPN

Optical design

Autocollimation/coaxial optics; no reflector minimum distance

Special feature

Detecting transparent objects

Light source

LED, visible red light

Wavelength

640 nm

Light spot size

Ø25 mm at 1.5 m

Adjustment

Potentiometer, 11 turns

Switching mode

Light/dark switching, selectable via L/D control cable

Power supply

10–30 V DC; short-circuit-protected network max. 8 A

Residual ripple

<5 Vpp; remain within supply tolerances

Current consumption

30 mA without load

Output current

≤100 mA

Response time

≤330 µs with resistive load

Switching frequency

1,500 Hz at light/dark ratio 1:1

Beam attenuation

>8%

Connection

Plug M12, 5-pin

Circuit protection

Supply reverse-polarity protection, interference suppression and output overcurrent/short-circuit protection

Protection class

III

Housing material

ABS plastic

Optics material

PMMA plastic

IP rating

IP66, IP67 and IP69K

Operating temperature

−30 to +60 °C

Storage temperature

−40 to +75 °C

MTTFD

823 years

Diagnostic coverage DCavg

UL file

NRKH.E181493 and NRKH7.E181493

Dimensions L x W x H (cm)

4.2 x 1.56 x 4.85

Physical Weight (kg)

0.12

Industrial Applications

1. Counting separated transparent containers

A container conveyor can position the sensor opposite a suitable reflector so each separated transparent container changes the returned light level. The documented clear-object sensing function provides the detection principle, while the switching output supplies events to compatible machine inputs. The actual container material, orientation and installed reflector spacing must be qualified during setup.

Problem Solved

A qualified transition provides a count input for transparent containers without a mechanical feeler, while the passive reflector avoids electrical wiring across the opposite side of the conveyor.

Transparent targets PNP/NPN Retro-reflective

2. Confirming a clear tray at a staging point

A handling station can aim the returned beam through the expected position of a transparent tray wall. A tray that remains at the staging point changes the received-light state, allowing the controller to evaluate sustained occupancy. Selectable light/dark switching adapts the signal logic, and the connection links the sensor to local machine inputs.

Problem Solved

A sustained detection state identifies a tray remaining at the staging point, supporting coordination of release and pickup after the actual tray and reflector arrangement have been qualified.

Tray occupancy Light/dark switching Clear-object detection

3. Checking transparent film presence

A film feeder can route transparent material through the returned optical beam and qualify the received-light change between film-present and film-absent conditions. A break or runout can then change the switching state. Visible red illumination assists positioning, while the documented enclosure rating supports installation in the machine environment.

Problem Solved

A qualified change of optical state gives the feeder controller an indication of missing film at the monitored point, supporting a coordinated response to interrupted material feed.

Transparent film Visible red light Material continuity