The DELTA MASTER-3 sensors are based on the principle of optical triangulation. A semiconductor laser projects a fine measuring line onto the surface of the material.
The image of this line is recorded by a geometrically ultra-stable matrix CCD-camera and evaluated with progressive digital image processing methods. An optical model of the surface is calculated and the material thickness determined from this which corresponds to that measured by conventional tactile, mechanical measuring instruments.
A material thickness is measured without contact up to 50 times per second at any sheet speed even on difficult surfaces on which conventional spot laser triangulation sensors fail due to the surface structure. The DELTA MASTER-sensor determines the material thickness from the distance between the sensor and the material surface. Various calibration, difference and compensation methods guarantee accurate and stable measurements even under harsh industrial conditions.