| 摘要 |
A measuring system for measuring a density of a medium flowing in a process line along a flow axis of the measuring system in the case of a medium which is variable as regards a thermodynamic state, especially a medium which is, at least in part, compressible. The measuring system includes therefor: At least one temperature sensor placed at a temperature measuring point, reacting primarily to a local temperature, theta, of medium flowing past, and delivering at least one temperature measurement signal influenced by the local temperature of the medium to be measured; at least one pressure sensor placed at a pressure measuring point, reacting primarily to a local, especially a static, pressure, p, of medium flowing past, and delivering at least one pressure measurement signal influenced by the local pressure, p, in the medium to be measured; at least one flow sensor placed at a flow measuring point, reacting primarily to a local flow parameter, especially a flow velocity, a volume flow or a mass flow of the medium to be measured, especially also changes of such, especially a flow parameter averaged over a cross section of the process line, and delivering at least one flow measurement signal influenced by the local flow parameter; as well as a measuring electronics communicating, in each case, at least at times, with the temperature sensor and the pressure sensor. The measuring electronics produces, with application both of the temperature measurement signal as well as also the pressure measurement signal, as well as also the flow measurement signal, at least at times, at least one density measured-value, especially a digital, density measured-value, representing, instantaneously, a local density, rho, which the flowing medium has at a virtual density measuring point, especially a virtual density measuring point predeterminably spaced from the pressure measuring point and/or from the temperature measuring point along the flow axis.
|
