Research On Synchronized Measurement Method And Device For Liquid Density And Viscosity

The density and viscosity are not only the important characterization of physical properties of liquid, but also have important effects on some production engineering or production. Study on the rapid method of measuring liquid density and viscosity has an important practical value to meet the needs of production process control. This paper aims to propose a new method for accurately and rapidly measuring liquid density and viscosity and to develop a test system.This paper summarizes status of methods and apparatus for rapidly measuring viscosity and density of room temperature liquid. Based on the analysis of the advantages and disadvantages of different methods, the author proposes a new method using a sampling density and viscosity of liquid synchronization rapid detection.Under the condition of a constant initial vacuum pressure, the sampling time and the change of the pressure in the sampling chamber were recorded and monitored during a quantitative liquid suction process. The liquid density was calculated by the pressure balance function among the hydrostatic pressure, the air pressure and the atmospheric pressure. At the same time, the kinematic viscosity was characterised using the measured liquid sampling time. Therefore, the goal was achieved for the simultaneous measurement of liquid density and viscosity double parameters. The simultaneous measurement system designed in this paper, mainly consists air supply unit,sampling unit, data acquisition and processing unit, and the test system software was written using Microsoft Visual Basic 6.0.More than ten kinds of standard liquid with the viscosity and density known in standard were measured using the device. The relationships between liquiddensity and air pressure above liquid, as well as the relationships between liquid column climbing time and kinematic viscosity of liquid, were established. The empirical formula for calculating the liquid density equation and viscosity were obtained. Furthermore, the comparative experiments were carried out between the new method and commercially available standard liquid viscosity and density tester. The test results for different standard liquid shown that, the testing errors of the new method for density and viscosity were within 0.5 % and 0.7 %,respectively. With the comprehensive consideration, the new synchronous detection method of liquid density and viscosity has the advantages of fast test speed and simple operation compared with the traditional test methods. It is not only suitable for normal temperature liquid detection, but also can be used for high temperature melt detection in the field of metallurgy, casting and other industry after further research and development.