Diffuse sensors

Transmitter and receiver in one housing: Detection performed by detecting the light reflected by the object.

Designed for outstanding detection performance – built to impress

The HT28C from Leuze – performance that sets industry standards

When performance is non-negotiable, the HT 28C diffuse sensor with background suppression is the ideal choice. These sensors combine decades of Leuze’s expertise into a series that sets new standards. Cutting-edge technology and outstanding performance meet exceptional cost efficiency – you only pay for the performance you need, and nothing more.

The HT28C is available with a variety of light sources (Power PinPoint® LED, laser, infrared), additional XL light spots, and various connection types. The sensors with background suppression offer reliable and cost-effective solutions for applications across various industries – performance that pays off through higher availability.

Hybrid design. Ready for anything

Designed for maximum flexibility, the 28C series features a hybrid housing: a cubic shape combined with a cylindrical M18 thread and an optical outlet. This allows the sensor to be mounted either from the side using the integrated fastening holes or from the front through a perforated plate via the M18 threaded part. For both options, Leuze offers additional mounting systems and brackets that enable particularly quick and easy installation. The compact 15 mm x 38 mm x 32.3 mm housing dimensions allow easy integration even in tight installation spaces. This makes this sensor series a true industrial all-rounder. With protection class IP69K and ECOLAB-certified housing, the sensor is also suitable for sensitive or harsh environments.

Advantages for you

Excellent background suppression and low black-and-white error for a wide range of installation spaces, including varied and close-proximity backgrounds as well as different objects
Multiple light sources (Power PinPoint® LED, laser, infrared) and an XL light spot in one housing with full mounting compatibility – a mechanical design suitable for all applications
Suitable for use even in harsh environments thanks to protection class IP69K – install it once and forget about it
Easy commissioning/setup, and adjustment thanks to the Power PinPoint® LED
IO-Link interface for diagnostic data and predictive maintenance
Compact housing: Suitable even for applications with limited installation space

Highlights

The light spot makes all the difference: small, bright and precise

The optical diffuse sensors with Power PinPoint® LED utilize innovative light source technology. Thanks to the newly developed LED, the sensors’ optical system generates a light spot that maintains its size, shape, and uniformity across the sensor’s entire working range. This significantly increases process reliability and substantially reduces the effort required for alignment and commissioning.

This enables significantly higher detection point precision, particularly in diffuse sensors.

Faster adjustment, more reliable detection

IO-Link-Schnittstelle zur Diagnose und Parametrierung

With the latest Leuze ASIC and IO-Link protocol, the 28C series offers expanded detection capabilities without compromise.

Maximum process stability:

Continuously monitor signal quality to detect deviations early
Comprehensive diagnostic data, such as operating hours, object counters, and device status, enables predictive maintenance exactly when it's needed

Maintain full control over your process:

Comprehensive timing functions (timers) for on/off delay and pulse suppression
Locator function: Quickly identify sensors via flashing LEDs
Quick and easy pinout configuration

Advantages for you: Greater transparency, increased system availability, and reduced downtime – for smarter and more efficient processes.

The 28C series detects where others fail

The 28C series sensor offers a wide variety of light spots and geometries to meet the requirements of various applications.

The PowerPinPoint® LED produces a round, uniform light spot, making it easy to identify the sensor’s exact switching points. The sensor’s reliable, precise response characteristics makes it much easier to integrate into the machine. This type of light spot enhances applications with parallel-operating systems as well as flexible leading-edge detection.

The laser light source is designed to detect even the tiniest objects. The laser light spot is the ideal solution even when detecting objects through narrow openings or holes. It is also the perfect choice for applications requiring precise positioning or leading-edge detection.

The 28C series also offers an optimal solution for objects with irregular or pierced surfaces, such as printed circuit boards or fruit baskets: It features a diffuse sensor with an XL light spot that ignores interference and disturbances where other sensors fail.

The infrared LED provides an additional option for distinguishing between different colors and reducing black-and-white errors.

Application

Lichttaster-HT-28C-zur-Erkennung-von-Kartons-auf-Foerderstrecken

Detection of cardboard boxes on conveyor systems

Requirement:

Flat, unfolded carton blanks are to be detected on a wide feeder. The blanks’ position, size, and color may vary.

Solution:

The HT28C or HT28CI reliably detect the cardboard strips virtually regardless of color due to their very low black-and-white error. The infrared light source helps eliminate potential interference from the environment.

Lichttaster-HT-28C-zur-Erkennung-von-Objekten-durch-Oeffnungen

Detection of objects through openings

Requirement:

Objects are to be detected along a closed conveyor line. The sensor is designed to reliably detect objects in the tunnel through a small opening. The covers vary in color, shape, and surface finish.

Solution:

The HT 28CL1 with a focused laser spot is ideal for detecting objects through small openings. The excellent background suppression and the very small black-and-white error ensure stable and reproducible detection.

Lichttaster-HT-28C-zur-Folienbeutelueberwachung

Feeding plastic bags in packaging machines

Requirement:

A sensor must monitor the continuous feed of plastic bags from the roll. Minor variations in position and surface must be tolerated. If the feed is interrupted or the roll is empty, a signal must be sent to indicate that it is time to change the roll.

Solution:

The HT 28C.XL diffuse sensor enables the detection of uneven or partially transparent objects. The hybrid housing enables easy integration into the machine, saving time and costs during installation and allowing mounting flexibility.

Technical features

Feature	HT 28C
Operating principle	Diffuse sensor with background suppression
Operating range	0.005 – 0.45m (Power PinPoint®LED) 0.005 – 0.6m (LED, infrared) 0.015 – 0.4m (laser) 0.005 – 0.05m (XL light spot)
Light sources	Power PinPoint® LED, red LED, infrared laser, red (Laser Class 1)
Switching frequency	1,000 Hz / 3,000 Hz (laser)
IO-Link	V1.1 (COM2)
Operation	Multi-turn spindle
Protection class	IP69K
Certifications	CE, UL, ECOLAB
Temperature range	-40°C – 60°C -40°C – 55°C (laser)
Connection	M12 / pigtail / cable
Housing dimensions (W x H x L)	15 x 38 x 32.3 mm