| 摘要 |
<p>The invention relates to a scanning device (1) for measuring physical properties of a moving fibrous web (2) which has two longitudinal edges and is intended to run in a predetermined path of movement past or through the scanning device (1). The device (1) has a carriage (11) carrying a scanning head (14). The carriage (11) is movably supported for movement transversely to the direction of movement of the web (2). A drive (12) is provided which imparts to the carriage (11) a reciprocating movement from one edge side of the web (2) to the other, during which the scanning of the web (2) is carried out. The scanning device (1) is fitted with means (21, 31, 32, 33, 36) associated with the carriage for providing, in essentially the same plane as the predetermined path of movement of the web (2), a planar web supporting surface at locations between the carriage (11) and the two longitudinal edges of the web (2) during passage of the web (2) past the scanning device (1). The invention reduces the occurrence of web breakage and improves the accuracy of the measurement.</p> |
