The Leuze KRTM 20M/N-20-6320-S12 (Part Number: 50113436) is a premier high-resolution multicolor contrast and print mark sensor belonging to Leuze electronic's proven Series 20 (Germany). Combining an RGB (Red, Green, Blue) multi-color LED transmitter system with precision autocollimation optics and an extraordinary 50 kHz switching frequency, this sensor resolves microscopic grayscale variations and color marks on challenging packaging materials at extreme web velocities.

KEY PRODUCT FEATURES AND OPERATIONAL ADVANTAGES:
1. Multi-Color RGB Light Source with Automatic Color Selection:
Utilizes a triple-color RGB LED transmitter array. During teach-in calibration, the internal microprocessor automatically analyzes contrast differentials between the target mark and background, selecting the optimal transmitter wavelength (Red, Green, or Blue) to achieve maximum optical signal contrast—even for pale pastel marks or yellow print on white backgrounds.
2. Ultra-Fast 50,000 Hz (50 kHz) Switching Frequency & 10 µs Response:
Boasting a rapid 50 kHz switching rate, a fast 10 µs to 20 µs response time, and an ultra-low 10 µs response jitter. It provides precise mark registration and knife cut synchronization on high-speed packaging machinery running thousands of units per minute.
3. Autocollimation Optics & Precision Vertical Light Spot (1.2 x 4 mm):
Features coaxial autocollimation optical architecture where transmitted and reflected beams pass through the same optical path, eliminating optical dead zones and allowing angled mounting to prevent direct glare reflections on glossy foils or metallic films. The concentrated 1.2 x 4 mm vertical rectangular light spot at 20 mm focal range tracks fine registration marks effortlessly.
4. Flexible Calibration (Static 2-Point Teach-in & Remote Input):
Supports static 2-point teach-in directly via an onboard membrane keypad or through an external remote Teach input line. Includes an integrated pulse-stretching time function (20 ms) to assist PLCs in capturing extremely short pulses reliably.
5. NPN Digital Output with Light/Dark Selectability:
Equipped with a solid-state NPN transistor switching output with pushbutton-selectable Light-switching or Dark-switching operation.
6. Heavy-Duty Diecast Zinc Housing – IP67 & IP69K Ingress Protection:
Built with a rugged diecast zinc enclosure weighing 300 g, engineered to resist severe mechanical shock and plant vibrations. Fitted with a scratch-resistant optical glass window, it is fully rated for IP67 and high-pressure IP69K washdown environments.

TYPICAL INDUSTRIAL APPLICATIONS:
• Form-Fill-Seal (FFS) & Flow-Wrapping Machinery: High-speed cut mark synchronization on confectionery, snack food, and noodle packaging film.
• Printing & Converting Presses: Print mark detection and web alignment on glossy foil, polybags, and aseptic liquid cartons.
• Cosmetic & Pharmaceutical Tube Filling: Alignment and orientation of registration marks on collapsible squeeze tubes prior to heat sealing.
• High-Speed Bottle Labeling Lines: Precise label edge tracking and registration mark sensing on automated beverage labeling equipment.

• Manufacturer: Leuze electronic
• Part Number / Model: KRTM 20M/N-20-6320-S12
• Order Number (Part no.): 50113436
• Series: Series 20 (Multicolor Contrast Scanner)
• Brand Origin: Germany
• Device Type: High-resolution print mark / contrast sensor
• Light Source: Multi-color RGB LED (Red, Green, Blue pulsed light)
• Optical System: Autocollimation optics
• Operating Range (Scanning distance): 20 mm ± 2 mm (18 ... 22 mm)
• Light Spot Geometry: Rectangular, vertical orientation
• Light Spot Size: 1.2 mm x 4 mm (at 20 mm operating distance)
• Optical Focus: Fixed focus
• Digital Switching Frequency: 50,000 Hz (50 kHz) / Selectable 25,000 Hz
• Response Time: 10 µs / Selectable 20 µs
• Response Jitter: 10 µs
• Time Function: Integrated 20 ms pulse stretching (selectable)
• Teach-in Methods: Static 2-point teach or dynamic teach-in
• Operational Controls: Onboard membrane keyboard
• Remote Teach Input: 1 DC teach input
• Supply Voltage (UB): 12 ... 30 V DC (Residual ripple 0 ... 15%)
• Open-Circuit Current: 0 ... 35 mA (Max. ≤ 60 mA)
• Digital Switching Outputs: 1 output
• Switching Output Type: Transistor NPN
• Switching Principle: Light/Dark switchable
• Max. Output Current: 100 mA
• Output Signal Voltage: High ≥ (UB - 2V), Low ≤ 2V
• Protective Circuits: Polarity reversal protection, short-circuit protection
• Status Indicators: LEDs for power/ready (ON LED) and mark detection (Q/T LED)
• Connection Type: M12 metal/stainless steel connector, 5-pin male (A-coded)
• Dimensions (W x H x L): 30 mm x 80 mm x 53 mm
• Net Weight: 300 g
• Mounting Type: Through-hole mounting via threaded inserts
• Housing Material: Diecast zinc metal housing
• Lens Cover Material: Optical tempered glass
• Ingress Protection: IP 67, IP 69K (Resistant to high-pressure washdown)
• Protection Class: Class III
• LED Group: Class 1 (according to EN 60825-1)
• Ambient Operating Temperature: -25 °C ... +60 °C
• Storage Temperature Range: -40 °C ... +70 °C
• Standards & Certifications: IEC 60947-5-2, cULus Listed