Displacement Measurement – Are you using the right sensors?

In a world of Industry 4.0, sensors must perform high speed measurements and provide high precision results to ensure reliable quality assurance.

Optical measurement techniques play an essential role in the increasing automation of manufacturing and inspection processes. Non-contact sensor technology is responsible for wear-free, fast, high precision and reliable measurements of manufactured components and their measuring points. This is a decisive advantage in online measurement, particularly if the target is in a difficult-to-access area. Measurement data is generally available in real time and so can be used to automatically correct and control the production process. Process automation can improve product quality and reduce raw materials and energy usage, which minimises production costs. For these purposes, a wide range of displacement sensors are available to suit different applications based on parameters such as measuring range, frequency response and accuracy.

The manufacturing of laminated glass, solar cells, flat screens and smartphone displays are challenging as they consist of several layers and different transparent materials. When manufacturing multi-layer, laminated and curved glass for airplanes, automotive and architectural applications, precise thickness measurement of each layer is important. Due to the high cycle rates involved, the measurements must be performed quickly and precisely. Confocal sensors master these tasks. They are compact, fast, easy to integrate, and ensure the highest reliability in almost any area where high precision is expected – from machine monitoring to fully automatic quality control of the final product.

Large plants and machinery such as stone mills or telescopic installations often work with hydrostatic bearings that are continuously supplied with liquid lubricant via an external pressure supply. In this case, eddy current displacement sensors are used since they can ‘see through’ the lubricant and provide sub-micrometre position control.

Laser triangulation sensors with their small spot size, large stand-off, fast measuring rate and very high precision find numerous applications in industry. One example is pick-and-place machines, where laser triangulation sensors are used to monitor the position of tiny components. They ensure that the components are positioned the correct side up, at the correct location and at the correct height. The requirements on the measurement technology are enormous; not only because the parts are extremely small, but also primarily due to the rapid change from shiny to matt surfaces. Laser sensor technology with Auto Target Compensation (ATC) provides fast control of different reflections and enables a smooth signal frequency of the distance signal, ensuring high measurement precision at all times.

Laser sensors are not only bound to one-dimensional measurements, as there is demand for multi-dimensional quality control in industrial production. Laser profile scanners are increasingly used for 2D and 3D profile and contour measurement applications. Their operating principle is based on the laser triangulation technique for two-dimensional profile detection. They detect, measure and evaluate the profiles on different object surfaces. While the laser scanners are giving 2-D information, you can get the third dimension by moving the laser scanner or the target object relative to each other. One such application that can benefit from laser scanners is the inspection of adhesive beading in smartphone housings.

With its high precision, measurement speed, compact size and fast data processing, non-contact measurement technology offers many benefits. The user can choose from different measurement systems. Each principle comes with its own advantages and limitations that all need to be carefully considered. As demanding applications require higher resolution, robustness, temperature stability, linearity or special mounting and installation conditions, Bestech Australia offers Micro-Epsilon sensors for special solutions and custom designs that are adapted to the customer’s specifications. Contact type sensors such as potentiometers, LVDTs and draw wires are also available. Factory-trained application engineers with specialised product knowledge will work with you to understand your requirements and recommend the right sensors for your application.