A measuring system for the precise measuring a density of a medium, flowing in a line. compressible. 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 signal, density measured-value representing, instantaneously, a local density, of the flowing medium at a virtual density measuring point, predeterminably spaced from the pressure measuring point and/or from the temperature measuring point, along the flow axis.