Double sheet metal monitors and thickness measurement devices monitor the automated destacking and separation of ferrous (Fe) or non-ferrous (NE) metal sheets in metal processing equipment (e.g. presses) with automatic feeding systems such as destackers, robots, feeders, etc. By detecting double sheets or thickness measurement, the presence of two or more sheets stuck together can be reliably detected and the process stopped before the tool or the machine itself are damaged. In the universal BDK system, especially the user-friendly BDK Compact or the very cost-effective Doublesheet-Sensors BDK Uno and Duo sensors (which do not need an evaluation device), you are certain to find an optimum Sheet Thickness Detector.