DETERMINATION OF BASIS WEIGHT OF A MATERIAL WEB USING A MICROWAVE SENSOR, WHEREBY THE DISTANCE BETWEEN THE MATERIAL WEB AND THE SURFACES OF THE MICROWAVE SENSOR IS BEING ADJUSTED TO A CONSTANT VALUE BY AIR CUSHIONS

摘要

A device for determining the weight per unit area of a moving material web, in particular a fibrous material web includes at least one microwave sensor that has an element for coupling the microwaves and a reference element. The coupling element and the reference element are located at a distance from one another in such a way that the material web can be moved therebetween. At least one microwave sensor element, the coupling element and/or the reference element can be moved such that the distances between the material web and the elements can be adjusted for or during the measurement of the moving material web.