Measuring system designed to measure the density of a medium - notably hydrogen, nitrogen, chlorine, oxygen, helium or compounds and/or mixtures thereof, such as carbon dioxide, water, phosgene, natural gas or air - flowing through a process pipe along an imaginary flow axis of the measuring system, said medium being variable, particularly at least partially compressible, with regard to a thermodynamic state, said measuring system comprising: - at least one temperature sensor located at a temperature measuring point (M θ), primarily reacting to a local temperature locale, θ, of medium flowing past, said sensor being designed to deliver at least one temperature measuring signal (X θ) that is influenced by the local temperature of the medium to be measured, - at least one pressure sensor located at a pressure measuring point (M p), primarily reacting to a local, particularly static, pressure, p, of medium flowing past, said sensor being designed to deliver at least one pressure measuring signal (X p) that is influenced by the local pressure, p, in the medium to be measured, as well as - measuring electronics that communicate at least intermittently with at least the temperature sensor and the pressure sensor, said electronics being designed to use both the temperature measuring signal and also at least the pressure measuring signal to generate at least intermittently at least one density measured value (X ρ), particularly a digital value, using at least a numerical compensation factor, particularly one saved digitally, said compensation factor representing momentarily a local density, p, which the flowing medium has at a virtual density measuring point (M' p), particularly at a predefinable distance from the pressure measuring point (M p) and/or the temperature measuring point (M θ) along the flow axis, - wherein the at least one compensation factor corresponds to a mobility - occurring along the flow axis of the measuring system and determined particularly in advance and/or during operation - of at least one thermodynamic state variable of the medium, particularly a temperature, a pressure or a density, and/or corresponds to a mobility - occurring along the flow axis of the measuring system and determined particularly in advance and/or during operation - of the Reynolds number of the flowing medium and is determined taking into consideration the actual medium to be measured, particularly the composition of said medium and/or its thermodynamic properties, particularly during a calibration of the measuring system with a known reference medium and/or during the commissioning of the measuring system on site; - and wherein the measuring electronics are designed to determine the at least one compensation factor using a predefined specific thermal capacity, C p, of the current medium, particularly recurring at least once during the commissioning of the measuring system and/or during the operation of the measuring system. - at least one temperature sensor located at a temperature measuring point (M θ), primarily reacting to a local temperature locale, θ, of medium flowing past, said sensor being designed to deliver at least one temperature measuring signal (X θ) that is influenced by the local temperature of the medium to be measured, - at least one pressure sensor located at a pressure measuring point (M p), primarily reacting to a local, particularly static, pressure, p, of medium flowing past, said sensor being designed to deliver at least one pressure measuring signal (X p) that is influenced by the local pressure, p, in the medium to be measured, as well as - measuring electronics that communicate at least intermittently with at least the temperature sensor and the pressure sensor, said electronics being designed to use both the temperature measuring signal and also at least the pressure measuring signal to generate at least intermittently at least one density measured value (X ρ), particularly a digital value, using at least a numerical compensation factor, particularly one saved digitally, said compensation factor representing momentarily a local density, p, which the flowing medium has at a virtual density measuring point (M' p), particularly at a predefinable distance from the pressure measuring point (M p) and/or the temperature measuring point (M θ) along the flow axis, - wherein the at least one compensation factor corresponds to a mobility - occurring along the flow axis of the measuring system and determined particularly in advance and/or during operation - of at least one thermodynamic state variable of the medium, particularly a temperature, a pressure or a density, and/or corresponds to a mobility - occurring along the flow axis of the measuring system and determined particularly in advance and/or during operation - of the Reynolds number of the flowing medium and is determined taking into consideration the actual medium to be measured, particularly the composition of said medium and/or its thermodynamic properties, particularly during a calibration of the measuring system with a known reference medium and/or during the commissioning of the measuring system on site; - and wherein the measuring electronics are designed to determine the at least one compensation factor using a predefined specific thermal capacity, C p, of the current medium, particularly recurring at least once during the commissioning of the measuring system and/or during the operation of the measuring system.