These innovative sensors are used, among others things, by manufacturers of modern packaging systems and labels. Before the labels are applied, the quality of the paper label is inspected because during storage or caused by process failures, the actual paper quality might deviate from the required one. Depending on the color, the paper is subsequently assigned to defined batch numbers. For this process, the color shade and the degree of whiteness or yellowness index of paper is exactly defined. The color graduation ranges from beige to white in all shades, the surface texture goes from matt to shiny.
Conventional color sensors find these slight color differences quite challenging. Sensors with standard illumination brighten the surface only from one direction. With structured surfaces, this leads to inhomogeneous reflection of the color. Consequently, color deviations occur since the optical impression of the color shade in shaded areas or depending on the viewing angle changes. Therefore, the sensor does not record the real color.
The new CFS2 color sensor is designed for the surface-independent color recognition and detects the finest of white nuances reliably. The CFS2-M20 circular sensor can be used for a measurement distance of 10-100 mm with a measurement spot size of 10 to 66 mm. Arranged at an angle of 22°, the sensor illuminates the measuring range with a 20 mm diameter in a circular fashion. The CFS2-M11 circular sensor uses the same measurement distance but also offers a larger illumination angle of 67° which provides a measurement spot diameter with 12 to 114 mm diameter.
The circular sensors homogeneously illuminate structured targets and achieve precise measurement results. Combined with the colorSENSOR CFO controllers, monitoring of dynamic processes at up to 30 kHz is possible. Repeatability is, depending on the controller, ΔE ≤ 0.5 or ΔE ≤ 0.3