A system is provided for measuring an analyte concentration in a body fluid sample, comprising at least one cartridge that contains consumables for multiple measurements, a data carrier which is affixed to the cartridge and contains calibration information for the consumables contained in the cartridge, a hand-held device that comprises a cartridge reception compartment including a reading facility for receiving a cartridge of this type and for reading its data carrier, a measuring facility for measuring the result of a detection reaction, a processor that is connected to the measuring facility and the reading facility for controlling the measuring facility and for analysis of a measuring signal. As an additional system component, at least one replaceable data storage unit is further provided in which supplementary data is stored. The data storage unit functions in combination with calibration information from the data carrier, wherein the hand-held device comprises an interface for transmission of supplementary data from the replaceable data storage unit to the device, and a consumables identification is stored on the data carrier and used by the processor after insertion of a cartridge to determine whether the consumables of the inserted cartridge, combined with the supplementary data that is available to the processor, renders a reliable measurement of an analyte concentration of a body fluid sample feasible.