Packaging quality control method and apparatus

摘要

The quality of a product, for example the degree of filling of cigarette papers, is non-destructively tested using reflectivity measurement. Compensation is provided for the effects of stray light in the measuring zone and the signals commensurate with the measurements performed on individual units of the object being tested are compared with the average of signals obtained through measurements performed on a preselected number of units of acceptable quality. The state of operability of the test apparatus may be self-checked during incremental periods between the testing of units.