A variety of methods exist for casting materials of various sorts onto a moving substrate. In the photographic film manufacture process it is conventional practice to cast, for instance, cellulose acetate films by a solvent cast method. In the solvent cast method a solution of cellulose acetate in a solvent is poured onto a moving casting surface. After sufficient evaporation of the solvent, the cellulose acetate film is peeled from the casting surface. A near infra-red (NIR) gauge is used for measuring the solvent content of the acetate film while on the casting surface. For measurement purposes, the NIR gauge needs to be mounted about 0.250 inches to about 0.375 inches away from the casting surface. The casting surface has a mirror finish and can easily be damaged. Protuberances or obstructions on film exceeding the dimensions of the spacing between the gauge and casting surface are caught between the NIR gauge and the casting surface. This generally results in damage to the finish of the casting surface and to the probe.
While there are no known attempts to solve the specific problem confronted by Applicants, U.S. Pat. No. 4,865,872, titled "Strip Inspecting Apparatus and Associated Method" by Pellatiro, Sep. 12, 1989, discloses a strip inspection apparatus wherein a linear sensor array is positioned above the surface of a strip for determining the position of the strip edges. Further, U.S. Pat. No. 4,797,301, titled "Method of and Apparatus for Applying a Fluid to a Bulk Commodity" by Ardley et al., Jan. 10, 1989 discloses a combination pivotally mounted apparatus for applying a fluid and for monitoring the thickness thereof to a material being conveyed. An obvious shortcoming of each of the aforementioned devices for solving Applicants' problem is that neither provides for a flexural assemblage that yields to contact by a surface protuberance thereby avoiding damage to the surface undergoing inspection.
Therefore, a need persists for a flexural probe assemblage for examining a sensitive web surface that can be arranged very close to the sensitive surface and can then pivot away from the sensitive surface when engaged by a protuberance on the surface without causing damage to the surface.