SYSTEM
The Leveller Check consists of laser distance gauges using the triangulation principle and an evaluation and visualization software. The number of sensors depend on the range of production; usual 7 up to 11 sensors. A standard PC is used as Human-Machine-Interface (HMI). The software shows the measurement results. This is done graphically and color coded. The color codes are calculated and based upon the specified tolerance limits. The sensors are mounted in a measuring frame above the plate. As the material temperature in this location can reach up to 1,000 °C, a double-walled insulated frame along with additional heat shields protect the sensors against heat effects. Separate cooling units maintain a constant air temperature inside the measuring frame, while a continuous air purge prevents soiling of the optical components.
THE MEASURING SYSTEM
The plate flatness is measured in 11 tracks across the plate width by the “LAP Leveller-Check”. The sensors use the triangulation method to measure the distance to the plate surface. The arrangement of the sensors is adapted to match the product spectrum. A speed signal from the leveller is used to allocate the cross-profiles along the plate length. Combining subsequent cross profiles yields the flatness information. This information is graphically displayed in the control pulpit of the leveller as I-Units, longitudinal and transversal profiles and colored topographical maps.
BENEFITS
Measurement of flatness after levelling allows optimal setting of the hot leveler. Immediately after the passing of a plate the leveling result is available for evaluation and the plate leveling can be repeated if needed. The leveller setting can also be optimized for the following plates and the flatness results will be used to permanently optimize the control model of the rolling train.
