Transparent materials such as clear glass, PET or thin plastic films pose challenges for many optical sensors. As such objects transmit light almost completely or reflect it unpredictably, classic reflective sensors are often overwhelmed.
However, in industrial applications – for example in the packaging, food, pharmaceutical or automotive industries – reliable glass detection is crucial for safe processes.
wenglor offers several sensor technologies that have been specially developed for transparent objects. Below we present the most proven sensor types.
Retro-reflex sensors with single-lens optics are among the most established solutions for detecting transparent objects. These so-called “clear glass sensors” work with a polarizing filter process and are designed to reliably detect even extremely transparent materials.
Advantages of these sensors:
These sensors are ideal for classic tasks such as object presence, glass edge detection or detection of transparent packaging on conveyor lines.
Ultrasonic sensors are one of the most universal solutions when it comes to difficult or transparent materials. As they do not work with light, transparency plays no role whatsoever.
They emit sound waves and measure the echo – and are therefore perfect for:
Advantages:
Ultrasonic sensors are therefore particularly suitable for applications in which a light solution would physically fail.
Time-of-flight sensors (ToF) with wenglor wintec technology offer very high process reliability for demanding object detection applications – especially in the medium and long range.
These sensors not only measure the presence of objects, but also their distance – and do so extremely robustly, even on difficult surfaces.
Particularly suitable for:
Strengths:
When very precise distance or position measurements are required – for example on glass edges, curves or structured glass surfaces – triangulation measurement comes into play.
A typical example is the P3PC342which is used in pharmacy picking machines to determine the exact position of glass containers or bases.
Advantages:
This technology is often used when a fine distinction in height or precise glass geometry is required.
Several proven technologies are available at wenglor for the detection of clear glass:
Application | Recommended technology |
Presence detection on conveyor lines | Retro-reflex sensors for clear glass |
Transparent objects independent of light | Ultrasonic sensors |
Distance measurement for longer ranges | ToF sensors with wintec |
Precise edge and height measurements | Triangulation sensors |
The selection depends heavily on factors such as range, material properties, ambient conditions and the desired measuring accuracy.
Job title