Features:
- Detects diffuse targets over an adjustable 200 to 2000 mm range.
- Accepts 12 to 240 V DC or 24 to 240 V AC supply power.
- Provides a selectable light-on/dark-on relay output with local status LEDs.
The emitter and receiver share one housing, so no separate reflector is required for target detection.
A yellow indicator follows the relay state, while a red indicator reports reduced optical reserve.
The PG9 terminal compartment separates the power pair from the normally open relay contact.
The Pepperl+Fuchs RLK39-8-2000/31/40a/116 RLK39 Diffuse Mode Photoelectric Sensor may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Pepperl+Fuchs RLK39-8-2000/31/40a/116 RLK39 Diffuse Mode Photoelectric Sensor Manuals,Datasheets,Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Following reflected infrared light into the relay decision
- Emission: The IRED sends modulated infrared light toward the target area.
- Reflection: The object returns part of that light to the receiver in the same housing.
- Evaluation: The sensor compares the received level with the range setting.
- Switching: The qualified detection state controls the relay according to the selected mode.
Relating target position, surface and sensitivity adjustment
- Reference target: The published range uses a standard white 200 mm by 200 mm target.
- Dark objects: Lower reflectivity reduces the usable distance and alignment margin.
- Adjustment: The sensitivity control is set after the object and background positions are fixed.
- Reserve warning: A red LED marks inadequate received-light reserve before stable detection is lost.
Separating the universal supply from the switched relay load
- Supply pair: Terminals 1 and 2 accept the documented AC or DC supply.
- Contact pair: Terminals 3 and 4 form the normally open relay output.
- Load limit: The external circuit remains within the relay voltage, current and power limits.
- Closed cover: The terminal cover must be secured to maintain the documented protection class.
Preserving alignment through installation and maintenance
- Rigid surface: The housing is mounted without distortion through its fixing holes or bracket.
- Cable preparation: The cable length and strip length follow the terminal-compartment drawing.
- Alignment: The optical axis is aimed at the required target position before sensitivity is set.
- Maintenance: Optical faces, fasteners and electrical connections are checked when the red LED indicates reduced reserve.