| 摘要 |
<p>A beam generator (2) creates a light beam (20) of rays (200) parallel to an axis Oy. The object (1) is maintained in the beam (20) by a support (3) comprising a cylindrical hole (30) of axis Oz, traversed by the object (1). Under the action, for example, of a pressure difference, the object (1) is pushed against the wall of the cylindrical hole (30) in such a manner that one of its generatrices (P) coincides with a generatrix (G) of this cylindrical hole (30). A receiver (5) measures the width (E), along Ox, of the shadow zone (4) created by the object (1). The support (3) may be driven in rotation about the axis Oz of the cylindrical hole (30) and in displacement according to an oscillatory movement of direction parallel to this axis Oz. The invention applies to the automatic measurement of the diameter of cigarettes, and variations of this diameter along the direction and the cross-section in which the measurements are made. <IMAGE></p> |
