Device for the continuous testing of the surface of a moving material web

摘要

Device for the continuous testing of the surface of a moving material web, in particular a web of plastics film, for projections such as stipples, projecting impurities and the like, characterised in that a plurality of piezoelectric sensors (7) which are mounted offset in a housing (1) transverse to the direction of motion of the web bear loosely against the surface of the web outside the housing with their scanning edges (8<a>) and are electrically connected to a common storage and evaluation unit. <IMAGE>