In automated lifting and conveying systems, the reliable detection of transport containers is crucial for a smooth process. It becomes particularly challenging when the objects are black – as is the case in many industrial applications. This is because black surfaces absorb light almost completely. Conventional sensors therefore detect too little reflected signal to ensure reliable switching.
For this application, wenglor offers two suitable alternatives: the P1KH019 and P1MH202 reflex sensors with background suppression. Both models work according to the triangulation principle, but differ in format, range and light source, thus enabling optimum adaptation to the respective installation situation.
With lifting devices or conveyor lines, sensors usually have to work in confined spaces. The working distances are often only a few centimetres, while the surfaces of the objects can vary greatly. Black boxes absorb so much light that classic reflex or energy sensors reach their limits. This leads to incorrect switching, standstills or unreliable results, especially if the objects are in motion.
This is where reflex sensors with background suppression come into play. They do not measure the intensity, but the angle of the reflected light. This allows the distance to the object to be calculated – regardless of its color, shape or surface finish.
If the available installation space is limited, the P1KH019 is a good choice. It works with blue light, which is particularly well reflected by dark materials due to its shorter wavelength. This significantly improves the detection performance on black plastic or metal surfaces. With a detection range of up to 150 mm, the P1KH019 is ideal for lifting devices, small conveyor lines or robot applications where sensors need to be installed in confined spaces. The test showed that the sensor delivered stable switching signals even when mounted almost directly on the edge of the crate – even with changing reflection properties.
Advantages P1KH019:
If a little more space is available or a greater range is required, the P1MH202 is the right alternative. It also works with background suppression, but uses laser light (alternatively also available as a red light version, e.g. P1MH101).
With a detection range of up to 200 mm, it covers greater distances and offers more mounting freedom thanks to its more robust format. This variant is particularly suitable for applications in which the crates or conveyed objects pass at slightly varying distances or when sensors cannot be placed directly on the edge.
Advantages P1MH202:
Both sensors are based on the same functional principle of triangulation, which means they work reliably even on highly absorbent surfaces. Thanks to the intelligent evaluation of the backscatter angle, the switching behavior remains stable – regardless of color, material or degree of gloss.
The choice of a suitable model depends on the respective installation situation and the required range: The P1KH019 scores points in tight spaces, while the P1MH202 impresses with greater flexibility and range.
