A reusable seal including an antenna, an opening sensor to sense the opening of a volume to be monitored and an electronic device coupled to the antenna and configured to communicate with a reader via the antenna. The electronic device is supplied with power only by the antenna when a reader is proximate to the antenna. The seal has a memory that may assume an active state or an inactive state. The seal is configured such that the memory may be activated only by the electronic device when the device is supplied with power to store an intact seal state in the memory, and the memory may be deactivated at any time when the opening sensor is actuated to store a non-intact seal state in the memory. The seal is configured to respond to a request from a reader regarding its state according to the memory state.