Abstract: A method of monitoring an element of a plant is disclosed which comprises the steps of: (a) producing an image representing the state of the element and recording the image in the form of a data set; (b) comparing the data set with a norm in order to determine a change in the state of the element; and (c) producing a signal which represents the change in the state of the element.

Abstract: A system for allowing to provide service and for charging the costs associated with providing the service to a vehicle or to a customer, which system comprises means for providing service to the vehicle, a vehicle recognition system capable of producing characteristic vehicle data, a customer recognition system capable of producing characteristic customer data, a data processing means which is connected to the recognition systems so as to receive the characteristic data, which data processing means includes a storage device including records containing characteristic data of the vehicle and the related customer, a system for comparing the produced characteristic data of the vehicle and the customer with the stored characteristic data, means for allowing the service to be provided when the produced characteristic data agree to one set of characteristic data of the vehicle and the related customer, and means for charging the costs to an account.