A method for extraction of zinc values from an aqueous alkaline solution of zinc, especially a solution obtained by the stripping of a galvanized coating from a ferrous metal product e. The portable device receives a first request signal from a communication controller and transmits a first response signal corresponding to the first request signal. The evaluation can be made from the different measurement voltages measured at the terminals. In a preferred embodiment this alignment channel is black or dark in color with a white or light-colored border. The message retrieval module receives a selection of the message identifier from the recipient device, retrieves the message from the non-transitory, non-persistent memory, and sends the message to the recipient device for presentation.