Method and measuring device for measuring at least one property of a moving web

摘要

The measuring device comprises at least one measuring head (3, 4) having a reference part (6), which comprises a reference surface (13) against which the moving web is supported. The reference surface (13) comprises a measuring area (25) in the inside of which the property of the web is measured. The reference part (6) is arranged in connection with the measuring head (3, 4) in such a way that below the reference part (6), there is a substantially open air space (17). The measuring head (3, 4) comprises means for generating negative pressure in the air space (17) below the reference part (6), and the reference part (6) comprises holes (14) formed through it, in such a way that the negative pressure generated in the air space (17) affects through the reference part (6) the space between the reference surface (13) and the moving web in such a way that the web is supported against the reference surface (13) substantially over the whole area of the measuring area (25). <IMAGE>