Apparatus and method for operating a device with a memory device, an evaluation device and a weighing unit. The weighing unit has a unique identification key. For the identification key of the weighing unit an associated characteristic identification key is stored in the memory means. The evaluation device derives from the determined with the weighing data from a record, which contains weight data. The evaluation reviewed the togetherness of the deposited in the storage device passkey of the weighing unit and the identification key of the current weighing unit. The evaluation means determines a positive verification status when the cohesion of the deposited in the memory device identification key and the identification key of the current weighing unit is detected. The evaluation device determines a negative test status if no matching passkey is detected in the storage device to the identification key of the current weighing unit. The record is output as a calibrated data set with a positive and as a non-calibrated data set with a negative test status.