In this article review of density and viscosity measurement methods is presented, including ultrasonic pulse echo methods, which are capable to measure these properties of polymer melts. The methods are presented according to measurement principles, methodology, accuracy and possibility to measure density and viscosity of polymer melts on-line during extrusion process. Such measurements are ver...

This document presents the principle of ultrasonic distance measurement is described, the main error sources of ultrasonic distance measurement are analyzed also. A method of improving precision of ultrasonic distance measurement in air, in which the transmission speed of ultrasonic wave if corrected by measured air temperature and the forward edge of receive wave can be determined accurately b...

Ultrasonic, used in security technology such as car collision avoidance and distance measurement, also can be used in detecting obstruction behind the car when backing up. In this paper, we analyze the interference of ultrasonic signal when transmitting and receiving, and then resolve it by software. There is a blind area and distance limitation in ultrasonic distance measurement .The cause of ...

application of automatic systems, including discharge measurement technology is one of the effective methods for improving delivery management, water use efficiency, flexibility, and performance of irrigation networks. several aspects such as hydraulic, technical, physical, environmental, economic, social, and managerial, have significant impact on these systems selection. due to diversity of t...

In this study, two kinds of nondestructive evaluation (NDE) techniques (rebound hardness and ultrasonic pulse velocity methods) are investigated for the effective maintenance of underwater concrete structures. A new methodology to estimate the underwater concrete strengths more effectively, named “artificial neural network (ANN) – based concrete strength estimation with the combination of rebou...

Ultrasonic measurements have been performed for comprehensive microstructural characterisation in 9 % Cr ferritic steels. The variation in grain size, the effect of solution annealing temperature on microstructure developed, the variation in microstructure of the weld joints, the effect of post weld heat treatment and precipitation behaviour during thermal ageing and creep testing have been suc...

Fast reduction of blood water volume due to ultra-filtration via hemodialysis machine and critical threshold of blood water volume can result in clinical complications such as hypotension. When blood water volume reduces during hemodialysis process, the concentration of blood forming elements will increase. One of the methods for the monitoring of the concentration changes is ultrasonic speed m...

The experimental study of air movement induced by natural ventilation in greenhouses requires a system to measure the air velocity "eld. A networked, two-dimensional sonic anemometer system was developed for simultaneous measurement of the instantaneous air speed and direction at 12 locations. The system performance was tested and validated against a mass #ow controller and a commercial, three-...