A system and method for tracking media is disclosed. At least one locking element is arranged for movement in a radial direction, with its opposite longitudinal sides being guided along guide surfaces on the first fitting part, and the locking element includes at least one tooth which cooperates, on its radially outer side, with toothing on the second fitting part for the purposes of locking. The source material may contain lithium carbonate. The internal strobe signal generator generates an internal strobe signal having a frequency which is higher than that of an input strobe signal according to a phase difference between the input strobe signal generated from the external device and a second input control signal. The data is configured for use by a particular analysis application.