Abstract: An apparatus for measuring the relative differential length of a sample of a web or sheet material. The apparatus includes a substantially flat surface adapted to support the sample. Air is removed between the sample and the substantially flat surface to position the sample in an unrestrained state. A translation member translates a plurality of non-contact sensors in a first direction along the length of the sample, whereby the plurality of non-contact sensors sense the distance from a reference plane to the sample and generate a signal representative of the distance sensed. A data collection system collects the generated signals and determines a relative differential length of the sample from the generated signals.

Abstract: Apparatus and method for measuring camber of a web material. As the web material is transported across a conveyance roller, a load cell disposed at each end of the conveyance roller measures the force applied by the web material to the conveyance roller for a particular width location of the web material. An electrical signal corresponding to the applied force is transmitted to a computer and manipulated to a camber measurement.

Abstract: An apparatus and method to measure a gap width distance, specifically the distance between the lip of a coating hopper and the tangential edge of a coating roller or the support on the roller, is disclosed herein. The apparatus includes a long range microscope coupled with a CCD camera to provide a computer with an image. From this image the computer calculates first and second derivatives of the light intensity values between each pixel and determines the pixel locations of the two edges.

Abstract: Method and apparatus for measuring the quality of the planar end surface of a wound roll comprising: optically projecting a line of light onto the planar end surface of the wound roll to generate and reflect an image of the line of light; focusing the reflected image onto an image sensor to obtain a data output; and feeding the data to a processor that measures deviations in the reflected image of the line of light that are caused by variations in the planar end surface of the wound roll.

Abstract: An apparatus and method for detecting the edge of a light sensitive photographic emulsion on a support is described. The method and apparatus include a pair of collimated infrared light sources for illuminating each edge of the support at an angle of incidence of greater than 0.degree. to about 45.degree.. Positioned above the edges of the support are a pair of CCD cameras. Light scattered by the support and emulsion is detected by the CCD cameras and the edges of the emulsion and the edges of the support are detectable. Signal means are used to generate a signal corresponding to the position of the emulsion on the support. A conventional guider receives the signal and positions the support accordingly.

Abstract: A method and apparatus for determining the flatness of a sheet material, and for determining the lateral alignment stability of a web or sheet material. The method for determining the flatness of a sheet material includes subjecting a portion of the sheet material disposed between two rollers to a longitudinal tension insufficient to remove internal compressive strains in the longitudinal direction, sensing by non-contact means the distance from a reference plane to the sheet material, and determining a cross-sectional profile of the portion.

Abstract: Non-contact measurement of the sharpness of the cutting edge of a slitting or chopping knife is made repeatably placing a capacitance sensor probe symmetrically over the cutting edge at a predetermined distance (nominal offset) from the calibrated sharp edge of the knife and measuring the capacitance to derive a measurement that varies with knife wear (increasing knife edge radius). A novel sensor holder allowing for repeatable precision placement of the sensor.

Abstract: A capacitance probe (10) includes readily removable outer layers (64,66) which facilitate its use in the field to measure the width of slots or clearances (12) of different widths; an optionally perforated guard electrode (64,66,76,82) which permits width measurements over wider side wall bands with minimal effect on sensitivity; convergent or tapered side edges (102) to ease insertion and movement of the probe and a carrier block (124) which ensures proper positioning of the probe within such slots.