Correlation Analysis of Probing Signals as a Special Case of the Digital Signal Processing Methods in an Ultrasonic Liquid Flow Measurement Applications

The paper discusses the analysis and comparison of the various widely known digital processing methods of ultrasonic probing signals in liquid flow measurement applications. A particular attention is paid to correlation methods with the possibility of the correlation function interpolation to provide a small measurement error in determining the flow velocity and the liquid flow rate. In the general representation, the described problem is reduced to achieving the required accuracy of the propagation times measuring of ultrasound waves through the liquid flow in the pipeline. In addition, some issues of digital signal filtering are discussed. The results of the performed mathematical modeling on the measurement error estimation of the temporal signals parameters are obtained for clamp-on flow-meters in close to real operating conditions and with the available limitations on the possible signal sampling rate.