A measuring system for precise measuring a density of a medium flowing in a pipe line. The measuring system comprises a temperature sensor and a pressure sensor. Both sensors communicate with a measuring electronics of the system. The measuring electronics are operable to provide, based on temperature measurement and pressure measurement, a provisional density measured value, especially according to one of the industrial standards AGAR, AGN NX-19, SGERG-88 IAWPS-IF97, ISO 12213:2006. Further, the measuring electronics provides, based on the provisional density measured value and a density correction value, which is dependant on a flow velocity of the medium, and temperature measurement, a density measured value, which differs from the provisional density measured value, and which represents the density to be measured more accurately.