Measuring density of flowing fluid using at least two measuring points

摘要

The method for density measurement uses at least two measurement points (M1, M2) in the fluid, a first or a second pressure signal (DS1, DS2) is obtained. Each of which contains a first component, at least approximately linearly dependent on a static pressure (Ps) in the undisturbed fluid flow. The first pressure signal (DS1) at least, contains a second component, at least approximately linear dependent on a dynamic pressure (Pd) in the undisturbed fluid flow. The second component is additively linked with the associated first component. A first measurement signal function (F1) is produced by difference building between the first and second pressure signals (DS1, DS2). This function is allocated to the density (rho) and to the square of the undisturbed also in certain cases the determined flow speed (W) of the fluid. By the determining of the fluid movement a second measurement signal function (F2) is produced, at least approximately independent of the density of the fluid, which is allocated to the undisturbed also in certain cases the determined flow speed. By combination and in certain cases transformation of the first and second measurement signal functions (F1, F2) a measurement signal function (Fd) allocated to the fluid density is produced.