Measuring system for a medium flowing in a process line

Abstract

The invention relates to a measuring system for measuring a density of a medium flowing in a process line, said medium being variable regarding its thermodynamic state, especially at least being proportionally compressible, along an imaginary axis of flow of the measuring system. The measuring system comprises at least one temperature sensor that is located in a temperature measuring point and that primarily reacts to a local temperature, theta, of a medium flowing past, said temperature sensor supplying at least one temperature measurement signal that is influenced by the local temperature of the medium to be measured, at least one pressure sensor that is located in a pressure measuring point and that primarily reacts to a local, especially static, pressure, p, of a medium flowing past, said pressure sensor supplying at least one pressure measurement signal that is influenced by the local pressure, p, in the medium to be measured, and at least one electronic measuring unit that at least temporarily communicates with at least the temperature sensor and the pressure sensor. The electronic measuring unit generates a provisional density value, using the temperature measurement signal and at least the pressure measurement signal, said density value representing a density which the flowing medium only apparently has in a virtual density measuring point that is especially interspaced from the pressure measuring point and / or the temperature measuring point along the axis of flow at a defined distance. The electronic measuring unit further generates at least temporarily at least one especially digital density value, which is different from the provisional density value, using the provisional density value and at least one correctional density value that depends on a flow speed of the medium and on the local temperature prevailing in the temperature measuring point, said correctional value being determined during operation time.

Description

technical field [0001] The invention relates to a measuring system for measuring the density of a medium flowing in a process line with a temperature sensor, a pressure sensor and measuring electronics, the medium being variable in terms of its thermodynamic state along a virtual flow axis of the measuring system , in particular at least partially compressible, the measuring electronics at least intermittently communicates with the temperature sensor and the pressure sensor and at least intermittently produces at least one density measurement which represents the local density of the flow medium as precisely as possible. Background technique [0002] In order to detect a measured variable (such as a thermodynamic state variable, density, or a measured variable derived therefrom) that describes the action of the process in a flowing medium, and to generate a measured value correspondingly representative of this measured variable, in industrial process measurement technology, i...

AI Technical Summary

Problems solved by technology

Correspondingly, for the aforementioned configurations, at flow velocities significantly less than 10 m / s, the sought-after measurement accuracy of about 0.1% to 0.5% can no longer be achieved

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