Patent ID: 6743338
Filing Date: 2004-06-01
Classification: G01B,Y10S

Abstract:
A method of measuring at least one property of a moving web, the method comprising the steps of measuring the property of the moving web with a measuring device having at least one measuring head with a reference part, supporting the moving web against a reference surface of the reference part and measuring the property of the moving web within a measuring area of the reference surface, wherein the reference part is arranged in connection with the measuring head in such a way that below the reference part there is a substantially open air space, and the reference part comprises holes formed through it, wherein the measuring head comprises at least one channel being in connection with the open air space below the reference part, the method further comprising supplying gaseous medium, through the at least one channel, between the measuring head and the moving web, so as to generate negative pressure in the open air space, which negative pressure is exerted on the web through the reference part in such a way that the negative pressure affects the moving web at different distances from the measuring area along the surface of the web such that the negative pressure causes the moving web to be supported against the reference surface substantially over the whole area of the measuring area.