Abstract: The integrity of the contents of containers (such as cartons containing arrays of cigarette packets) is ascertained in an apparatus wherein a continuously or intermittently operated conveyor advances successive containers of a series of such containers onto and beyond a weighing device (such as a strain gage) which transmits signals denoting the weights of successive containers to a circuit wherein such signals are compared with a reference signal denoting the weight of a container having satisfactory contents. If the difference between the weight of a freshly weighed container and a desired or required weight exceeds a preselected value, the respective container is expelled from the path for acceptable containers. The reference signal can be updated upon completed weighing of each acceptable container.