DDetermine quality of a packing bag

I have a use case to determine the quality of a packing bag filed with wheat flour. It is made to fall from a height of 2 m and see if the bag breaks, How do I sense the breakage? Thanks and regards

sensers are being used to identify open seal (broken bag) in packaging system, most commonly photo cell with sendor in one side reciver in other side or refector type photocell are being used in the conveyor