Abstract: A method for the continuous, quasi-static and contactless determination of the width of hot rolled products within a rolling mill train, preferably of hot wide band, via diode line cameras on which the two side edges of the illuminated rolling mill product are projected. The position of the illuminated edges of the rolling mill product is measured by alternating-current fed lamps in successive measuring cycles of 10 msec. Immediately following the exposure, the resulting electrical charge on the diodes within a measuring cycle in a period of 200 usec used, is scanned (sampled). Scanning is always at the maximum of intensity of illumination of the lamps. The electrical charge on the diodes for facing edges may be simultaneous, and the bright-dark transitions of the projected edges may be detected in the diode lines. The diodes darkened by the rolled product are counted in the diode lines above the two edges.