Leuze KRTM 3B/6.2121-S8 Contrast Sensor
Leuze KRTM 3B/6.2121-S8 contrast sensor offers 14.5 mm range, RGB LED, push-pull transistor output for marking detection tasks applications. Manufactured by Leuze, this Leuze Contrast Sensor belongs to the KRT Series and supports 14.5 mm ± 2 mm operating range, RGB LED light source, push-pull transistor switching output, 10,000 Hz switching frequency, 10–30 V DC supply, focused beam optics, and IP67 protection.
| Brand | Leuze |
| Product Type | Contrast Sensor |
| Product | KRTM 3B/6.2121-S8 |
Leuze KRTM 3B/6.2121-S8 Contrast Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Design | Cubic |
| Dimension (W x H x L) | 31 mm x 53 mm x 80.1 mm |
| Special version | Teach input Time function |
| Operating range | 14.5 mm ± 2 mm |
| Beam path | Focused |
| Light Source | LED, RGB |
| Light spot size [at sensor distance] | 1.5 mm x 6.5 mm |
| Light spot orientation | Horizontal |
| Type of light spot geometry | Rectangular |
| Light beam exit | Front |
| Wavelength | - |
| Supply voltage UB | 10 ... 30 V, DC |
| Number of teach inputs | 1 Piece(s) |
| Number of digital switching outputs | 1 Piece(s) |
| Switching output | Transistor, Push-pull |
| Switching principle | Light switching (PNP)/dark switching (NPN) |
| Switching frequency | 10,000 Hz |
| Response time | - |
| Con:1 Function | - |
| Type of connection | Connector |
| Thread size | M8 |
| Type | - |
| Material | Metal |
| No. of pins | 4-pin |
| Housing material | Plastic |
| Housing color | - |
| Type of fastening | - |
| Type of display | - |
| Operational controls | Teach button |
| Ambient temperature, operation | -30 ... 55 °C |
| Ambient temperature, storage | - |
| Degree of protection | IP 67 |
The KRTM 3B/6.2121-S8 Leuze Transistor Push-pull Output Contrast Sensor is designed for precise contrast detection in industrial automation environments. The KRTM 3B/6.2121-S8 operates with a 14.5 mm operating range, RGB LED light source, focused beam path, and push-pull transistor output. It is part of the KRT Series and is used where reliable mark and contrast recognition is required.
This contrast sensor is applied in conveyors, packaging machinery, printing lines, and automated assembly systems. Its light switching and dark switching capability enables stable detection of marks and color differences at high speeds. Teach input functionality allows quick setup, while the compact housing supports integration in space-constrained automation equipment.
The KRTM 3B/6.2121-S8 reflects Leuze’s engineering focus on dependable sensing solutions. With IP67 protection, M8 connector interface, and stable electrical performance, it is suitable for continuous industrial operation. As part of the Leuze KRT Series, it supports consistent contrast sensing where durability and signal stability are essential.

