Leuze LRT-8/24.04-50-S12 (50041840) Luminescence Sensor — UV LED, M12, IP67

LEUZE · LRT-8 SERIES · UV LUMINESCENCE · 24V DC · M12 · IP67 · 1PC

The Leuze LRT-8/24.04-50-S12 (material number 50041840) is a fluorescence / luminescence sensor from the Leuze LRT-8 series that emits UV light and detects the visible emission returned by luminescent marks, fluorescent inks, clear adhesives, security pigments, and chalk coatings that are otherwise invisible to standard photoelectric eyes. It is commonly dropped into packaging, printing, pharmaceutical, lumber and label-verification lines where Allen-Bradley, Siemens, Mitsubishi and other control platforms need a single discrete signal for a mark that has no contrast against its background. The integrated M12 connector, 24V DC supply and IP67 housing make it a drop-in detection head for retrofit or new factory automation cells.

Key Technical Specifications & Overview

The LRT-8/24.04-50-S12 is part of Leuze’s LRT-8 family of luminescence sensors, designed to detect fluorescent markers on materials that are transparent, dark, patterned or high-gloss. The “04-50” suffix denotes a 50 mm focal / range window, “24” indicates a 24V DC supply, and “S12” designates the integrated M12 4-pin connector. The housing is rated to IP67 for wash-down and dusty environments, and the switching frequency is high enough to follow fast conveyor and rotary indexing applications.

Application Scenarios & Where It Fits

A luminescence sensor earns its place on the line when the target “mark” has no visible contrast against its background. Common deployments include:

• Packaging lines — detecting clear PVA / hot-melt glue beads on cardboard cartons, glued flaps, or window patches where conventional contrast sensors cannot see the glue line.
• Printing & converting — registration of fluorescent print marks on transparent film, metallized foil, or shrink sleeve; feed synchronisation into a ControlLogix or SIMATIC S7 cut-to-length controller.
• Pharmaceutical — verifying presence of blister-pack foils, security inks on cartons, or fluorescent tamper-evident seals before a vision inspection station.
• Lumber & wood — reading chalk or crayon grade marks on graded lumber that pass over a roller conveyor, feeding a length-optimisation saw.
• Label & mail — detecting fluorescent postal marks, paper labels on dark substrates, or clear pressure-sensitive labels on coloured backings.
• Robotics & pick-and-place — used as a trigger sensor in front of a FANUC, Yaskawa or Mitsubishi robot cell to fire a grip / reject at the right moment.
• Process & discrete lines running under Omron, Schneider or Panasonic PLCs that need a clean 24V PNP signal back to the scan cycle.

Integration & Wiring Notes

The LRT-8/24.04-50-S12 is designed to be wired straight into a standard 24V PLC input module using a 4-pin M12 patch cord (such as a Leuze CB-M12 pre-wired cable or any M12 A-coded 4-pin sensor cable). A typical pin-out is:

• Pin 1 (BN, brown): +24V DC supply
• Pin 3 (BU, blue): 0V DC (return)
• Pin 4 (BK, black): Switching output (PNP / NPN, depending on variant)
• Pin 2 (WH, white): Often used for teach-in, remote threshold, or alarm output — consult the device label

When integrating into a multi-brand cell, common pairings are:

• Allen-Bradley 1734-IK / 1756-IB16IF discrete input — PNP sourcing
• Siemens ET200SP DI 8x24VDC HF or S7-1200 SM 1221 DC input
• Mitsubishi MELSEC iQ-R RX40C7 or FX5-16EX/ES input module
• Omron CP1W-20EDT1 expansion input block
• KEYENCE KV-N24EX / DL-PN input module on a KV series PLC
• Schneider Modicon M340 BMXDDI1602 or M580 DDI 32-input

Keep the cable length short, route it away from VFD motor leads, and use a shielded M12 cordset if the sensor sits next to a servo amplifier. When you are unsure of the discrete I/O structure, run the sensor’s signal through a Leuze signal-conditioning relay or a small automation relay to make the I/O card “see” a clean 24V. For raw register-level signal conditioning or scale work, the PLC Analog Calculator helps you sanity-check thresholds before commissioning.

Installation & Commissioning Tips

• Mounting distance: Aim the beam at the 50 mm focal window — the sensor works best with the mark passing at the centre of the optical axis, not at the near or far edge.
• Angle & shading: Mount the LRT-8 at a 10–25° tilt relative to the moving web or surface to avoid specular reflection from glossy packaging, shrink sleeve or metallized film.
• Teach / set: Use the potentiometer or teach button on the back of the housing to learn the fluorescent mark on a reference target, then save the threshold. A second teach against a clean background prevents false triggers from ambient UV.
• Background suppression: A dark or coloured backing generally gives a better signal-to-noise ratio than a white or reflective backing — black conveyor belts and matte anodised fixtures are preferred.
• UV safety: The UV LED is in UV-A range, but prolonged direct exposure to the eyes should still be avoided. Position the sensor so the beam stops on the target, not on operator-facing glass.
• Cleaning & environment: The IP67 housing tolerates wash-down, but the optical window should be wiped with a lint-free cloth and isopropyl alcohol whenever dust, paper dust, or glue build-up is visible. Use the AI Diagnostic Tool if a sensor begins to false-trigger after a seasonal change.
• Signal diagnosis: If you are seeing intermittent triggers, cross-check the wiring and threshold on a Hex to Float trace or with the Modbus CRC calculator when the sensor is being polled over a gateway module.

Procurement, Warranty & Lead Time

Unit of sale: 1PC. The Leuze LRT-8/24.04-50-S12 (50041840) is supplied individually boxed with the standard factory calibration. Lead time: most orders ship from our Shenzhen — Hong Kong sourcing base within 3–7 business days for in-stock units, and within 2–4 weeks for factory-fresh back-orders. Warranty: 12 months against manufacturing defects, with worldwide shipping by DHL / FedEx / UPS and a quote returned within 24 hours on business days. KOEED is an independent multi-brand industrial automation distributor — we are not a Leuze subsidiary, but we keep the LRT-8 family, matching cables, brackets and signal-conditioners on the shelf for fast dispatch.

For larger panels or panel-builder lots, we can also cross-source adjacent Leuze photoelectric & luminescence sensors, the LRT 8/24.04-50-S8.3 M8 variant, and the higher-range LRT-8/24.04-150-S12 from the same family. Many of our customers bundle a Leuze sensor order with Allen-Bradley, Siemens, Mitsubishi, Omron, Fanuc, Schneider, Yaskawa, Panasonic and KEYENCE spare parts in the same BOM, and we quote the lot as a single shipment. Send your part list to Moritta@KOEED.COM and we will return availability and price within 24 hours.

Cross-reference & migration queries welcome. Quote the Leuze LRT-8/24.04-50-S12 (50041840) alongside any Allen-Bradley, Siemens, Mitsubishi, Omron, Fanuc, Schneider, Yaskawa, Panasonic or KEYENCE part numbers on the same BOM and send to Moritta@KOEED.COM.