Lasertriangulation
On top and bottom side of the extruded sheet two laser displacement sensors are scanning in a constant distance to the sheet.

Measuring principle:

These laser-triangulation sensors with high resolution and excellent linearity are designed for precise measurements in industrial applications.

Each sensor is guided on two linear bearings across the sheet and are driven by servomotors. On the basis of a calibration curve of the measuring frame (detected on a calibration scan without sheet) the measured values of the laser sensors determine the thickness profile and it is displayed on the screen.