Fully Developed Turbulent Pipe Flow -- Decay of Disturbances in Turbulent Pipe Flow -- Optimal Characteristic Parameters for the Disturbances in Turbulent Pipe Flow -- Measurement of Velocity and Turbulence Downstream of Flow Conditioners -- Signal Processing of Complex Modulated Ultrasonic Signals -- Vortex-Shedding Flow Metering Using Ultrasound -- Ultrasonic Gas-Flow Measurement Using Correlation Methods -- Ultrasound Cross-Correlation Flow Meter: Analysis by System Theory and Influence of Turbulence -- Effect of Area Changes in Swirling Flow -- Errors of Turbine Meters Due to Swirl -- Investigation of Unsteady Three-Dimensional Flow Fields in a Turbine Flow Meter -- How to Design a New Flow Meter from Scratch -- Effects of Disturbed Inflow on Vortex Shedding from a Bluff Body -- Correction of the Reading of a Flow Meter in Pipe Flow Disturbed by Installation Effects -- How to Correct the Error Shift of an Ultrasonic Flow Meter Downstream of Installations.Flow meters measure the volumetric flow rate in a pipeline. Most meters are based on deriving a signal from the fluid flow and calibrating the signal against the volumetric flow rate. The calibration is done in fully-developed flow, and the same state of flow must exist at the meter’s position when it is in practical use. This book addresses two major fluid mechanical problems in flow metering: the analysis of signal generation in turbulent pipe flow, which explains the function of the meter beyond a simple calibration, and the possible use of a meter in non-developed flows. These problems are investigated with reference to, and examples from, a variety of meters, e.g. ultrasound cross-correlation meters, vortex meters, and turbine meters. Studying these problems requires consideration of specific phenomena in turbulent non-developed pipe flow, as caused by installations, and finding special solutions with signal processing, both of which are included in the book.