The relative mass inspection can be made stably even for a lightweight and the large number of products such as individually-packaged ones and high-speed transportation which cannot be supported by the auto checker. For example, when inspecting dressing in a small bag, the dispersion observed in the conventional systems is greatly suppressed.
“Foreign objects” included in the product, “relative mass” and “shape” excluding the package can be inspected simultaneously. In the inspection of the shape, the system contributes to quality improvement by inspecting cracks, chippings, length/width, area, and other items.