The invention relates to a contact-less identification device comprising a flat conducting structure as an electromagnetic sensor or transducer, and more particularly the invention relates to contactless cards, hybrid cards and radio operated electronic labels and tags. The memory device achieves high density through the use of a compact sense amplifier circuit that employs a single transistor to sense stored dynamic data. The exhaust system may also have an oxidation catalyst located within the exhaust passageway upstream of the reduction catalyst to provide a desired ratio of NO:NO2 to the reduction catalyst, and an exhaust gas recirculation loop. The system is capable of recording, storing and transmitting individual operator performance data relating to proper detections, missed detections, and false alarms, i. The purge bag includes at least one port, such as a needle-free valved port, configured to receive fluids from the intravenous tubing. Each of the sensor devices includes three half-bridge circuits each of which has a pair of spin valve magnetic resistances that are connected in series in such a manner that the magnetization directions of spin fixed layers of the spin valve magnetic resistances are opposite to each other.