Research and Development in Measurement and Testing Technology

Online Thickness and Profile Measurement for Flat Products

A wide variety of flat products such as boards (e.g. mineral and particle boards) or sheets (e.g. rolled sheet metal, strips and slab ingots) frequently require continuous measurement of their surface profiles directly in the manufacturing process. The data obtained can be used to inspect quality as well as to control the particular process.

Point measuring systems with fixed measuring paths or oscillating systems are often used. Radiometric or point measuring laser ranging sensors are also widely used. Such systems are only cost effective when measurements large widths have to be scanned. Solutions with cascaded laser light-sectioning sensors that scan linearly furnish an alternative.

Cascaded Laser Light-sectioning Sensors

In keeping with the requisite path width and measurement uncertainty, such thickness and profile measurement systems are configured from several linear laser light-sectioning sensors inclined toward the direction of material transport. The sensors are calibrated and spatially oriented in a common coordinate system with a fixed reference to the target. While the target is moving along the underside of the system, measured data is captured at equal distances and complete profile cross sections are computed from this data online and visualized. The measurement of a single side is compared with a reference measurement or a measurement of two sides to continuously determine a vertical profile or a thickness profile.

The Fraunhofer IFF is an expert in configuring and implementing systems solutions for specific applications, which take online measurements over large widths rapidly at a high resolution in the direction of measurement.