SICK WL12G-3P2572 Miniature Photoelectric Sensor

(Order No.: 1053535)

Product Series: W12G Miniature Photoelectric Sensor | Principle: Coaxial Polarized Retro-reflective (Auto-collimation, integrated polarizing filter to suppress specular reflection)

✅ Model Code Definition

WL: Retro-reflective photoelectric sensor

12G: W12G square die-cast zinc housing series

3: PinPoint red LED with polarization

P: PNP output

2572: Version code, supports transparent object detection with one-touch Teach-in setup

📌 Core Electrical Specifications

📌 Mechanical & Environmental Data

Dimension: 15.5 × 48.5 × 42 mm, die-cast zinc housing

Connector: M12 5-pin male

Protection Class: IP66 / IP67

Operating Temperature: -40℃ ~ +60℃

Weight: Approx. 120g

Included accessory: Mounting bracket BEF-KH-W12

📌 Key Features

1. Coaxial Optics + Polarizing Filter: Detects transparent objects (PET bottles, films, glass), suppresses specular reflection from smooth surfaces
2. One-touch Teach-in: One-click threshold setting, two attenuation modes for transparent materials
3. PinPoint Light Spot: Small light spot for precise positioning, uniform beam at long distance
4. Wide-temperature metal housing, suitable for harsh industrial environments (packaging, logistics, automated production lines)

📌 Pin Assignment (M12 5-pin male)

1: Brown DC+

2: White Auxiliary input / External Teach-in

3: Blue DC-

4: Black PNP signal output

5: Grey Function pin

📌 Typical Applications

Transparent bottle detection, film/web processing, packaging conveyor lines, object presence detection, conveyor counting, sheet/workpiece presence inspection.

📌 Replacement & Same-series Reference

WL12G-3N2572: Same specs, NPN version (Order No.1053530)

WL12G-3P2572S02: Special variant for short-range transparent detection

Recommended reflectors: PL80A, P250F

📌 Troubleshooting

1. Unstable transparent object detection: Re-run Teach-in, select Mode II (high attenuation); clean lens and reflector
2. False triggering: Check polarization alignment; always use polarized retro-reflective type for glossy surfaces; avoid direct strong light hitting lens
3. No output: Verify power supply and M12 pinout, ensure load current ≤100mA

📌 HS Code Reference

Photoelectric sensor: 8525801300 (for customs declaration only, subject to final customs ruling)

WL12G-3P2572 VS WL12-2B430 Comparison Table

WL12-2B430: Legacy W12 retro-reflective sensor, without coaxial polarization and Teach-in for transparent objects; WL12G-3P2572: New generation W12G, specialized for transparent bottles and films

Replacement Guidelines

1. If WL12-2B430 was used for opaque workpiece detection: Mechanical mounting can be reused, but cable termination needs rework (4-pin → 5-pin)
2. If the station detects transparent bottles / films: The legacy WL12-2B430 is inherently unsuitable for this application; upgrade to WL12G-3P2572 for stable detection

Domestic Alternative Selection List (Polarized Retro-reflective, Transparent Object Detection, Equivalent to WL12G-3P2572)

Selection priority: Polarizing filter + Teach-in function required for stable PET/film detection; standard domestic retro-reflective sensors cannot substitute!

✅ Recommended Alternatives (Transparent object capable, polarized retro-reflective, PNP, M12 connector)

1. LANBAO PR-TM20D-P (First Recommendation)

Principle: Polarized retro-reflective, supports PET bottle & transparent film detection, with Teach-in

Sensing range: 0~4m, PNP output DC10~30V

Housing: W12-style square metal body, M12 5-pin, compatible mounting hole layout

Advantages: Established domestic brand, strong ambient light immunity, widely used in packaging industry to replace SICK, stable lead time

Application: Filling lines, transparent bottle presence check

2. HEYI PG-TM40P

Polarized retro-reflective, one-touch Teach-in, dedicated transparent object detection

0~4m range, PNP, M12 5-pin, metal housing IP67

Advantages: Widely adopted in lithium and packaging industries, resistant to dust and oil contamination

3. SODRON PR20-TM40P

Polarized retro-reflective with Teach-in, 4m range PNP M12

Metal housing, wide temperature range -30~+60℃, cost-effective

⚠️ Economy Alternatives (Opaque objects only, cannot detect transparent bottles, equivalent to legacy WL12-2B430)

Note: These lack coaxial polarization & transparent detection algorithm, transparent materials will pass through and cause missed detection!

F&C CR-40P: Polarized retro-reflective, 4m, PNP, potentiometer adjustment, M12 4-pin

MEIJIN PR-TM40P: Standard polarized retro-reflective, potentiometer adjustment

📌 Selection Notes

1. Transparent object detection requirement: Polarizing filter + Teach-in. Ordinary retro-reflective photoelectric sensors cannot replace WL12G-3P2572
2. Connector: M12 5-pin preferred, request pin definition matching SICK WL12G-3P2572 to minimize wiring modification
3. Reflector: PL80A can be reused, compatible with domestic sensors
4. Testing recommendation: For thin transparent film / glass bottle applications, on-site sample testing is mandatory to verify no penetration false trigger

📌 Pin Compatibility Remarks

WL12G-3P2572 M12 5-pin:

1 Brown DC+｜2 White External Teach-in｜3 Blue DC-｜4 Black PNP Output｜5 Grey Function Pin

Most domestic 5-pin alternatives adopt this pinout. Specify pin definition same as SICK WL12G-3P2572 during procurement.

WL12G-3P2572 Application Scenarios

Core positioning: Coaxial polarized retro-reflective photoelectric sensor for transparent objects, equipped with Teach-in, wide-temperature metal housing. Primary use: PET bottles, glass, transparent film detection; also compatible with ordinary opaque workpiece detection for humid, dusty, low-temperature production lines.

1. Food & Beverage Packaging Industry (Main Application)
2. PET empty bottle inspection on blow molding / filling lines: Empty bottle in-position counting, missing bottle detection, bottle body / bottom presence confirmation. Legacy WL12 series easily suffers light penetration and missed detection on empty transparent bottles; this coaxial polarized model reliably identifies PET bottles.
3. Glass / pharmaceutical vial detection: Oral liquid bottles, beer glass bottles, reagent vial in-position check and missing bottle detection on conveyor; IP67 withstands water washdown in wet cleaning stations.
4. Transparent packaging film, shrink film monitoring: Film presence detection and film-break alarm on packaging & sleeve wrapping machines. Ultra-thin transparent films can be reliably detected via Mode II high-attenuation Teach-in.
5. Finished transparent plastic tray / blister pack detection: In-position and missing part detection for food trays on conveyor lines.
6. Pharmaceutical & Cosmetic Industry
7. Presence detection and sorting counting for transparent reagent bottles and cosmetic bottles on conveyor.
8. Web break monitoring for transparent aluminum-plastic packaging films.
9. Clean filling lines: Metal housing resists cleaning chemical corrosion.
10. Film & Web Processing Industry
11. BOPP, PET transparent web: Web presence detection, web break emergency stop alarm.
12. Web feed monitoring on laminators and slitting machines to prevent idle operation without web material.

⚠️ Heavily wrinkled films require on-site Teach-in tuning.

4. Logistics & Packaging Automation
5. In-position detection and sorting trigger for transparent courier bags and sealed transparent plastic packages.
6. Detection of transparent packaged goods inside cartons. (Opaque workpieces are also supported, but this model’s advantage is not for plain carton inspection).
7. General Custom Automation (Harsh Environment Stations)
8. Low-temperature applications: Cold warehouse conveyor workpiece detection (-40℃ capability, not available on legacy WL12-2B430).
9. Sheet metal & plastic part in-position detection. (Works for opaque parts, but this is a downgrade application with poorer cost efficiency).
10. Pick-and-place robot, transfer station workpiece presence signal; PNP output directly connects to PLC.

✅ Suitable Operating Conditions

Detection of transparent / semi-transparent materials (PET, glass, transparent film) where ordinary retro-reflective sensors suffer light penetration and false switching;

Humid, washdown, dusty, low-temperature environment;

High-speed conveyor, up to 1500Hz switching frequency for high-speed line counting;

Compact installation space, small W12 square housing;

One-click calibration available; re-Teach to compensate lens / reflector dust accumulation.

❌ Not Recommended Applications

1. Dark light-absorbing objects, thick black rubber: Excessive light attenuation, diffuse photoelectric sensor recommended instead.
2. Highly specular polished metal sheets: Polarization reduces interference but strong specular reflection may still cause disturbance.
3. Distance >4m: Exceeds sensing range.
4. Tiny gaps / miniature objects: Fiber optic sensor recommended.

Application Selection Distinction vs Legacy WL12-2B430

WL12G-3P2572: Preferred for → Transparent bottles, transparent films, glass, low-temperature / washdown lines

WL12-2B430: Preferred for → Opaque workpieces only, normal temperature dry lines, no transparent object identification required