A measurement system comprising: a network, said network is an in-building wireless network or a wired network; a measurement apparatus provided with a first set of lot identification codes (24 1 ',...24 n '), said measurement apparatus is a handheld diagnostic device and said measurement apparatus is configured to use a consumable reagent in a measurement process, said consumable reagent is provided to a test strip and said consumable reagent having an associated lot identification code, said measurement apparatus is configured to transmit over said network said associated lot identification code of said consumable reagent when said associated lot identification code fails to match any of said first set of lot identification codes (24 1 ',...24 n '); a host apparatus provided with a second set of lot identification codes (24 1,....24 n) each having at least calibration data (32 1,...32 n) associated therewith, said host apparatus is a data management system and a portable reader configured to read a lot data file from a removable machine-readable memory and to communicate the lot data file to the DMS via the wireless network and/or the wired network, said lot data file 30 containing a set of lot identification codes 24 1,...24 n which are each associated with a respective set of calibration data 32 1,...32 n, wherein said calibration data (32 1,...32 n) is specific to one or more lots of a consumable reagent; said measurement apparatus comprises a lot identification code reader which is configured to read said associated lot identification code of said consumable reagent; said host apparatus is configured to receive said associated lot identification code of said consumable reagent transmitted from said measurement apparatus over said network, to subsequently identify whether the received said associated lot identification code matches any of said second set of lot identification codes (24 1,....24 n), and to provide at least said at least calibration data (32 1,...32 n) associated with a lot identification code in said second set of lot identification codes (24 1,....24 n) matching said associated lot identification code to said measurement apparatus over said network. a network, said network is an in-building wireless network or a wired network; a measurement apparatus provided with a first set of lot identification codes (24 1 ',...24 n '), said measurement apparatus is a handheld diagnostic device and said measurement apparatus is configured to use a consumable reagent in a measurement process, said consumable reagent is provided to a test strip and said consumable reagent having an associated lot identification code, said measurement apparatus is configured to transmit over said network said associated lot identification code of said consumable reagent when said associated lot identification code fails to match any of said first set of lot identification codes (24 1 ',...24 n '); a host apparatus provided with a second set of lot identification codes (24 1,....24 n) each having at least calibration data (32 1,...32 n) associated therewith, said host apparatus is a data management system and a portable reader configured to read a lot data file from a removable machine-readable memory and to communicate the lot data file to the DMS via the wireless network and/or the wired network, said lot data file 30 containing a set of lot identification codes 24 1,...24 n which are each associated with a respective set of calibration data 32 1,...32 n, wherein said calibration data (32 1,...32 n) is specific to one or more lots of a consumable reagent; said measurement apparatus comprises a lot identification code reader which is configured to read said associated lot identification code of said consumable reagent; said host apparatus is configured to receive said associated lot identification code of said consumable reagent transmitted from said measurement apparatus over said network, to subsequently identify whether the received said associated lot identification code matches any of said second set of lot identification codes (24 1,....24 n), and to provide at least said at least calibration data (32 1,...32 n) associated with a lot identification code in said second set of lot identification codes (24 1,....24 n) matching said associated lot identification code to said measurement apparatus over said network.