Product Description

The KEYENCE PR-M51N3 is a compact, self-contained transmissive photoelectric sensor designed for precise object detection in space-constrained environments. With a detection distance of up to 1.2 meters, it features two NPN outputs: one for Dark-ON operation and another for Light-ON, providing versatile control options. The sensor employs a red LED light source at 650 nm and offers a rapid response time of 0.5 ms for Dark-ON and 2.7 ms ON → OFF, 0.5 ms OFF → ON for Light-ON. Its robust construction includes an IP67 and IP69K-rated housing, ensuring durability in harsh industrial settings. The PR-M51N3 is ideal for applications requiring compact size without compromising on performance.​

Technical Specifications

• Model: PR-M51N3
• Type: Transmissive (Through-beam)
• Output Type: NPN
• Shape: Mini-slim
• Cable Connection: 3-meter cable
• Detection Distance: Up to 1.2 meters
• Control Outputs: 2 outputs (Dark-ON and Light-ON)
• Response Time:
• Dark-ON: 0.5 ms
• Light-ON: ON → OFF: 2.7 ms, OFF → ON: 0.5 ms
• Light Source: Red LED, 650 nm
• Spot Diameter: Not specified
• Control Output: 30 VDC or lower, 50 mA or lower
• Leakage Current:
• 3 kΩ load: ≤0.3 mA
• 1 kΩ load: ≤0.5 mA
• 0.2 kΩ load: ≤1.5 mA
• Residual Voltage:
• ≤1.0 V for ≤10 mA
• ≤1.5 V for 10–30 mA
• ≤2.0 V for 30–50 mA
• Power Supply: 10–30 VDC (including ripple)
• Current Consumption:
• Transmitter: 11 mA
• Receiver: 16 mA
• Environmental Protection: IP67 (IEC60529), IP69K (DIN40050-9), NEMA 4X, 6P, 13
• Operating Temperature: -25 to +55°C
• Storage Temperature: -25 to +75°C
• Operating Humidity: 35% to 85% RH (no condensation)
• Insulation Resistance: ≥20 MΩ at 500 VDC
• Withstand Voltage: 1,000 VAC, 50/60 Hz for 1 minute
• Vibration Resistance: 10–55 Hz, 1.5 mm double amplitude, 2 hours in each direction
• Shock Resistance: 1,000 m/s², 6 times in each direction
• Material:
• Case: SUS316L stainless steel
• Lens cover: Polysulfone
• Cord protector: Polymethylpentene
• Filler: Polyester-based resin
• Weight: Approximately 90 g
• Accessories: Instruction manual​