| 摘要 |
<p>The proposal is for an opto-electrical measuring process for determining cross-sectional dimensions especially of web-like objects with reference to at least one straight line at the cross-sectional periphery and touching it at at least two points, and devices for implementing this process. A light beam which is moved inside a measuring area in a parallel shift exceeds limits of a shadow of the object in the measuring area at measurable places in the measuring area. The same light beam after being deviated or another light beam is used to provide point illumination of the surface of the object at a predetermined angle and the distance of the light beam axis at the position of a given shadow border to this illuminated point is found by its display at an angle differing from the illumination angle and the evaluation of the position of the image by triangulation calculation laws. By shifting the entire measuring system in relation to the orientation of the cross-section of the object and about an axis parallel to its longitudinal axis, the curve of the distance found undergoes a detectable unsteadiness which is characteristic of that shifted position of the measuring system at which the axis of the light beam at the position of the given shadow boundary touches the cross-sectional periphery at at least two separate points.</p> |
