Device for measuring the speed of products in movement, in particular metal rolled products in a rolling line, and relative method

Abstract

Device for measuring speed of oblong products moving along feed direction and emitting radiations, in particular rolled metal products in rolling line, including two radiation sensors, disposed reciprocally at close distance respectively defining an optical observation window, at pre-arranged distance from each other. Each window covers the image of an advancing product determinate portion equal to relative window width, irrespective of portion's movements transverse to feed direction. Sensors observe the presented product portion, on each occasion, in correspondence with associated windows consecutively along feed direction, and measure continuously intensity of radiation from the product portion in correspondence with the windows. Electronic processing unit determines, by processing electric signals associated with detected radiation intensity and arriving from sensors, using algorithms based on the correlation principle, time taken by the product portion to transit from first window to second, successive window, and then, based on distance between windows, calculates product speed.