For thickness measurement, OPTIMESS laser triangulation sensors, OPTISCAN laser triangulation scanners or light section sensors and OPTIMESS shadow measuring systems are used. The advantages of the laser measuring technique in the field of thickness measurement are:
no material contact
Independent of the colour of the material by control of the laser power
independent of the composition of the material
high local resolution due to small measuring spot
high measuring frequency (up to 50 kHz)
great distance from material possible In measurements on hot surfaces possible
Thickness measurement (single and multi-track)
The thickness measurement is performed directly at the point where the laser beam hits the object in the case of stationary objects and along the line which the laser point projects onto the material in the case of measuring objects passing by underneath the sensor. The measurement can be made as a reference measurement with one sensor or As a thickness measurement with two sensors per measuring track. C-brackets, 0-frames or complete measuring modules with automatic calibration and their own drive belts are available as measuring frames.
Linear thickness measurement (scanning or traversi
This thickness measurement takes place with OPTISCAN laser scanners or light-section sensors or over greater widths with a traversing mechanism and two punctiform OPTIMESS laser sensors. The lateral position is picked up as an additional value apart from the distance information by the laser scanners so that the thickness or the thickness profile along the scanned line is recorded. Over smaller widths the laser scanners or light-section sensors offer the advantage that no additionally moved parts are necessary and scanning frequencies of about 20 Hz are possible. On the other hand, the traversing mechanics, designed as a C-frame, offer the possibility of reaching measuring widths up to 5 metres.
Thickness measurement according to the shadow prin
In the shadow principle with OPTILINE sensors a laser line of parallel light is generated and projected on a CCD line opposite. When a material Is Inserted In the measuring gap this leads to a partial shadowing of the laser line on the detector. For thickness measurement it is necessary for the material to be measured to be deflected by a roller. The difference between the roller (zero) and the material surface picked up by the shadow measurement system is the material thickness.