The ET328.3/4P-M12 is an advanced energetic diffuse reflection sensor developed by Leuze electronic GmbH + Co. KG. It is designed to provide reliable and precise object detection based on reflected light. With a combination of robust construction and sophisticated sensing capabilities, this sensor suits a wide range of industrial automation applications.
Series: 328
Sensing Principle: Diffuse reflection
Light Source: Red LED (620 nm)
Signal Type: Pulsed light
Light Classification: Exempt group (EN 62471)
The sensor exhibits a strong ability to detect objects based on surface reflectivity:
| Surface Reflectivity | Guaranteed Operating Range | Operating Range Limit |
|---|---|---|
| White (90%) | 0.001 – 0.7 m | Up to 1.0 m |
| Gray (50%) | 0.001 – 0.59 m | Up to 0.85 m |
| Gray (18%) | 0.003 – 0.39 m | Up to 0.55 m |
| Black (6%) | 0.005 – 0.28 m | Up to 0.4 m |
Supply Voltage: 10 – 30 V DC (incl. residual ripple)
Residual Ripple Tolerance: 0 – 15%
Current Consumption: 0 – 20 mA
Output Configuration: 2 PNP digital outputs (light/dark switching)
Max Switching Current: 100 mA
Switching Frequency: 500 Hz
Response Time: 1 ms
Readiness Delay: 300 ms
Connector Type: M12, 4-pin, A-coded (Male)
Pin Assignment:
Pin 1: V+
Pin 2: OUT 2 (Dark switching)
Pin 3: GND
Pin 4: OUT 1 (Light switching)
Housing Material: Plastic (ABS) and Stainless Steel (V2A)
Lens Cover: Plastic
Dimensions: Ø18 mm x 46 mm
Thread Size: M18 x 1 mm
Weight: Approx. 20 g
Color: Black/Silver
Protection: IP67 rated
LED Indicators:
Green (steady): Sensor ready
Yellow (steady): Object detected
Control: Teach button for configuration
Operating Temperature: -40°C to +60°C
Storage Temperature: -40°C to +70°C
Protection Class: III
Standards Compliance: IEC 60947-5-2
Certifications: c UL US
The model code ET328.3/4P-M12 provides insights into the sensor configuration:
ET328: Energetic diffuse sensor series
3: Teach-in via button
4P: PNP outputs, light and dark switching
M12: M12 connector with 4-pin configuration
KD U-M12-4A-V1-050: Straight M12 connector, 5m cable
KD U-M12-4W-V1-050: Angled M12 connector, 5m cable
BT D18M.5: Rigid L-shaped bracket, stainless steel
BTU D18M-D12: Adjustable mounting system, 360° rotation
BT 328M: Included mounting clamp for 18 mm rods
This sensor is not a safety device and should not be used for personnel protection.
Only trained personnel should install and operate the sensor.
For UL compliance, ensure use within Class 2 circuits and approved cable assemblies.
A list of compatible accessories and device types can be found at www.leuze.com.
For reliable object detection across various reflectivity levels, the ET328.3/4P-M12 sensor provides high performance, robust design, and flexible integration into automation systems.
| Issue | Possible Cause | Solution |
|---|---|---|
| Sensor does not power on | No supply voltage or incorrect wiring | Check power supply (10–30V DC); verify M12 pin connection |
| Green LED is off | Sensor not powered or faulted | Ensure power supply is active and within rated range |
| Yellow LED does not turn on | Object not detected or object has low reflectivity | Check object distance, surface color, or alignment |
| Erratic output signal | Interference or unstable supply voltage | Ensure stable power and avoid electrical noise sources |
| Output always ON | Sensor may be in teach-in mode or misaligned | Verify teach button not pressed, re-align sensor |
| Output always OFF | No object detected, sensor misconfigured | Use target with higher reflectivity, check range setting |
| Detection range inconsistent | Dirty lens, varying object reflectivity | Clean lens, verify object type and distance consistency |
| Sensor gets warm | Overcurrent or incorrect load | Check output load (≤100 mA), ambient temp must be < 60°C |