Balluff BOS00K3 Photoelectric Sensor

(Full order code: BOS 18KF-PA-1QD-S4-C)

Type: M18 cylindrical retroreflective photoelectric sensor with transparent object detection capability

🔹 Core Technical Specifications

Light source: Red LED with polarizing filter

Sensing range: 0～4.5 m (requires reflector)

Supply voltage: 10～30 VDC

Output: PNP, switchable NO / NC (normally open / normally closed)

Connection: M12×1 4-pin male connector

Mechanical dimension: M18 threaded cylinder, Φ18 × 81.5 mm

Housing material: PBT plastic; optical window: PMMA

Certifications: CE, UKCA, cULus

Weight: Approx. 33.3 g

HS Code: 85365019

🔹 Key Features

Transparent object detection: Reliably detects transparent films, glass bottles and clear plastic parts-this is the core advantage of this model.
Straight flat optical window, fits standard M18 mounting holes.
Visible status LED on the side for easy on-site commissioning.
Red light with clear light spot, simple alignment with the reflector.

🔹 Typical Applications

Transparent material inspection on packaging lines, glass bottle detection, transparent film break monitoring, workpiece counting on conveyor lines, position confirmation in material handling & logistics systems.

🔹 Accessories & Replacement Options

Must be used with a retroreflector (retroreflective principle; cannot detect targets without a reflector).

Interchangeable variants within the BOS 18KF series (different cable types, NPN output or IO-Link versions).

Domestic alternatives: M18 retroreflective photoelectric sensors with transparent detection function; verify 4.5 m range, PNP output and transparent sensing performance before replacement.

🔹 Pin Assignment (M12 4-pin Connector)

1: Brown-DC+

2: Black-Switching output

3: Blue-DC 0V (GND)

4: White-NO/NC function switching

White wire open-circuit = NO (default); white wire connected to GND = NC.

BOS00K3 (BOS 18KF-PA-1QD-S4-C) Commissioning & Troubleshooting Guide

Operating principle: Retroreflective photoelectric sensor optimized for transparent object detection. A reflector is mandatory; it does not work as a diffuse sensor.

On-site Commissioning Procedure (follow step by step)
Wiring Check

M12 4-pin pinout:

1 Brown: DC+ 10~30V

3 Blue: DC 0V

2 Black: PNP output

4 White: NO/NC switching

White wire floating: NO; white wire shorted to GND: NC

Never short positive and negative terminals; supply voltage must not exceed 30 VDC.

Mounting & Reflector Selection

Recommended original balluff reflectors: BOS-R10, BOS-R20. Generic reflectors work but reduce stability for transparent targets.

Keep the sensor face parallel to the reflector; deflection angle < 5°.

Keep operating distance between 0.3~4 m; avoid the full 4.5 m maximum range, leave 10% safety margin for stable operation.

Transparent workpieces must pass directly through the light beam between sensor and reflector; avoid oblique beam occlusion.

Beam Alignment

Power on and slowly adjust the sensor angle until the green LED stays steadily lit (receiving reflected light from the reflector).

Insert the transparent workpiece into the beam: green LED turns off (signal triggered). Remove the workpiece, green LED lights up again.

Center the red light spot on the reflector for best anti-interference performance.

Environmental Notes (critical for transparent detection)

Detection stability varies with material thickness and refractive index: thick glass bottles are easier to detect than thin PET films.

Condensation, oil stains or scratches on transparent surfaces will easily cause missed detections.

Avoid direct strong sunlight or high-bay lighting shining onto the optical window.

Common Faults, Causes & Solutions

Fault Phenomenon	Root Cause	Remedy
Green LED never lights up after power-on (no return light)	① Power polarity reversed; ② Reflector dirty/missing; ③ Misaligned angle; ④ Supply voltage below 10 VDC; ⑤ Dirty optical lens	Check positive/negative wiring; clean or replace reflector; re-align beam; measure supply voltage; wipe the sensor window
LED keeps on even when transparent workpiece blocks the beam	① The beam is not fully blocked by the transparent part; ② The film is ultra-thin with very low light attenuation; ③ The reflector is too close; ④ Ambient stray light interference	Adjust beam position to ensure full occlusion; shorten sensing distance; add anti-glare shielding; switch to polarized reflector
Random signal flicker / false triggering	① Lens or reflector contaminated with dust/oil; ② Vibration causing angle drift; ③ Shiny surrounding surfaces reflecting light back; ④ Voltage fluctuation	Regularly clean optical surfaces; lock the sensor mounting nut; install polarizing filter; stabilize the power supply

Full Model List-BOS 18KF Series (Balluff M18 Straight-Body Photoelectric Sensors)