| 摘要 |
The dimensions of the cross-section of girders are checked, especially during rolling, by means of the coefficient of asymmetry calculated from measurements of the sides of the upper edge of the flange, the upper face of the web near the connecting fillet with the flange and the lower edge of the flange, at each of the two ends of the web. The measurement relating to the upper face of the web is carried out by triangulation by means of an optical rangefinder (9-13) located above the girder. The measurement relating to the upper (23) and lower (17) edges of the flange is carried out by two triangulations, each by means of a lamp (30; 29) serving as an intense light reference behind the girder and a receiver (28; 27) capable of detecting the location of the image of the transition between the illuminated zone and the shaded zone. <IMAGE> |
