Patent ID: 8266957
Filing Date: 2012-09-18
Classification: G01F

Abstract:
1. An apparatus for determining and/or monitoring the mass flow of a fluid medium through a pipeline, or through a measuring tube, comprising: two temperature sensors and a control/evaluation unit, wherein: said two temperature sensors are arranged in a region of a housing facing the medium and are in thermal contact with the medium flowing through the pipeline, or through the measuring tube; a first temperature sensor of said two temperature sensors is heatably embodied, and a second temperature sensor of said two temperature sensors provides information concerning current temperature of the medium; said control/evaluation unit, on the basis of primary measured variables, such as temperature difference between said two temperature sensors and/or heating power, which is fed to said first temperature sensor, ascertains mass flow of the medium through the pipeline; said control/evaluation unit, in ascertaining mass flow, provides a correction value for the mass flow and/or for the primary measured variable and/or for a measured value derived from the primary measured variable; and said control/evaluation unit, in ascertaining the correction value, takes into consideration heat exchange by forced convection and heat exchange by free convection between said temperature sensors and the medium, wherein: said control/evaluation unit ascertains the correction value for the mass flow and/or for the primary measured variable and/or for the measured value derived from the primary measured variable as a function of temperature and flow velocity of the fluid medium; and said control/evaluation unit ascertains the correction value for the mass flow and/or for the primary measured variable and/or for the measured value derived from the measured variable as a function of the term (√{square root over (T)}·u), wherein T is the temperature of the fluid medium and u the flow velocity of the fluid medium.