The typical inspection cycle of mcf CHECK
The typical inspection cycle is as follows:
- Search for the first edge position to the left of the entire strip, in order to predict as a first approximation the expected positions for all the other edges;
- Positioning on each measurement area, image acquisition and actual measurement of the edge position; from all the positions of the edges it is possible to obtain all the widths, both of the metallized and transparent zones, as well as the average positions of the various bands (metallized and transparent);
- Quantitative evaluations and comparisons with the product model can be carried out from all the position information of the edges and the centers of the bands (metallized and transparent);
- The positions of the bands will allow to define the positions of the areas where to carry out the “local” gap measurements, both of the transparent strips and of the metallized connections;
- The positions of the bands will allow you to define the positions of the zones where the resistivity measurements can be made using the 4-contact probe (for example in the center of the bands); consider that the camera and the probe are arranged integral on the same sturdy mobile equipment; the measurement of the resistivity is carried out by approaching the 4-contact probe to the film, by means of a small vertical axis (also electric and numerically controlled, in order to have a more accurate control and so as not to require pneumatic feeding on the car);
- The positions of the bands will also allow defining the positions of the areas where optical density (OD) measurements are to be carried out; these density measurements will always be carried out by the same high resolution (spatial) camera, but in a different mode, ie with high dynamics (at 12 bit, equal to 4096 levels of brightness, compared to the “normal” images used for geometric evaluations which are 8-bit, equal to 256 levels of gray); this high dynamic resolution (4096 values) allows for reliable optical density measurements within the range between zero and 3 OD (0.1% transmission); the absolute value of the measurement will be calibrated through sample filters as well as by the absence of film corresponding to zero OD.
At the end of the inspection cycle, the system will produce a complete report with all the measurements and evaluations carried out, on a text file in CSV format (compatible directly with Microsoft Excel and other software), in order to carry out all the statistical analyzes (on a single or on more tests).