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AssigneeMetso Automation Oy
InventorsJussi Graeffe, Timo Saikanmäki, Mauri Ojala, Jari Koivu, Hannu Moisio
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The measuring device comprises at least one measuring head having a reference part, which comprises a reference surface against which the moving web is supported. The reference surface comprises a measuring area in the inside of which the property of the web is measured. 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. The measuring head comprises means for generating negative pressure in the air space below the reference part, and the reference part comprises holes formed through it, in such a way that the negative pressure generated in the air space affects through the reference part the space between the reference surface and the moving web in such a way that the web is supported against the reference surface substantially over the whole area of the measuring area.
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.
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, and generating negative pressure 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, wherein at least one property of the moving web is measured optically.
A measuring device for measuring at least one property of a moving web, the measuring device having at least one measuring head with a reference part, the reference part having a reference surface against which the moving web is arranged to be supported to measure the property of the web and the reference surface comprising a measuring area within which measuring area the property of the web is arranged to be measured, whereby the reference part is arranged in connection with the measuring head in such a way that below the reference part, there is substantially open air space, wherein the measuring head comprises at least one channel which is in connection with the open air space below the reference part and which is arranged to supply a gaseous medium between the measuring head and the moving web in such a way that the supply of the gaseous medium is arranged to generate negative pressure in the air space, the reference part comprising holes formed therethrough at different distances from the measuring area such that the negative pressure generated in the air space is arranged to affect, through the holes formed through the reference part, between the reference surface and the moving web in such a way that due to the effect of the negative pressure, the moving web is supported against the reference surface substantially over the whole area of the measuring area.
A measuring device for measuring at least one property of a moving web, the measuring device having at least one measuring head with a reference part, the reference part having a reference surface against which the moving web is arranged to be supported to measure the property of the web and the reference surface comprising a measuring area within which measuring area the property of the web is arranged to be measured, whereby the reference part is arranged in connection with the measuring head in such a way that below the reference part, there is substantially open air space, the measuring device comprising means for generating a negative pressure in the air space, the reference part comprising holes formed therethrough at different distances from the measuring area such that the negative pressure generated in the air space is arranged to affect, through the holes formed through the reference part, between the reference surface and the moving web in such a way that due to the effect of the negative pressure, the moving web is supported against the reference surface substantially over the whole area of the measuring area, wherein the measuring head comprises at least one optical measuring means for measuring a variable expressing at least one property of the moving web.
Dependencies are inferred from the claim text.