To provide a low cost system which allows even medical laymen to make reliable measurements of analyte concentration in a body fluid sample.

A system 1 for measuring analyte concentration in a body fluid sample includes: a consumable member 3 containing a detection reagent; a magazine 2 containing the consumable member 3 for making multiple measurements; a data storage medium containing calibration information for the magazine 2; a portable device 4 having a magazine accommodating chamber equipped with a reader device for reading data from the data storage medium; a measurement device for measuring detection reactions; and a processor connected with the measurement device and the reader device. The system 1 includes at least one exchangeable data memory containing complementary data which is used in conjunction with the calibration data stored in the data storage medium. The data storage medium stores a consumable means identifier which allows the processor to identify whether or not the complementary data provided to the processor by the consumable member 3 of the magazine 2 inserted into the portable device 4 can be used in combination to reliably measure analyte concentration in a body fluid sample.