Three-in-one flowmeter

摘要

The flowmeter comprising a first flow passage with a fixed cross section geometry and a second flow passage with a variable cross section geometry measures the volume and mass rates of fluid flow through the flowmeter as well as the density of the fluid. The variable cross section geometry of the second flow passage varies as a function of the dynamic pressure of the fluid flow and the difference in the volume or mass rate of the fluid flow between the two flow passages varies as a function of the variable cross section geometry of the second flow passasge. The volume or mass rates of the fluid flow through the two flow passages are measured and the dynamic pressure of the fluid flow is determined therefrom, whereupon the volume and mass flow rates of the fluid flow and the density of the fluid are determined from the data on the volume flow and the dynamic pressure, or from the data on the mass flow and the dynamic pressure.