Research Of Intelligent Test Device For High-temperature Melt Viscosity

In industry production, the requirement of high temperature melt viscosity data improves the study of high temperature melt viscosity testing. Because of the close relationship between viscosity and temperature, the study of high temperature melt viscosity test needs the theoretics of temperature control and viscosity test. At present, the theoretics of viscosity test and the theoretics of temperature control have reached high level. These theoretics make good base for the study of high temperature melt viscosity test. There have been some products of high-temperature melt viscosity test at abroad. But, we lag behind abroad in designing the production that is used for above 1000℃melt viscosity test.The high temperature melt viscosity test instrument designed in this paper is to test the temperature between 1000℃and 1500℃. According to the conditions that are required by high temperature melt viscosity test instrument in performance, the performance of temperature control and the performance of software operation, in designing this instrument, there are three sections research that are viscosity test, temperature control and software design of the test system.At first, by analyzing the existed theoretics of viscosity test, the optimal theory that fits the high temperature melt viscosity test instrument is found in this paper. The factors that influence precision of viscosity test are analyzed in detail. According to the theoretics of chosen viscosity test, the system structure is constructed. Base on the requirement of temperature control, the heating system of test instrument is designed.Secondly, the relationship between viscosity and temperature is analyzed. When the temperature changes 1℃, liquid viscosity changes almost 1% to 10%. It can be found that the precision of temperature control directly affects the accuracy of viscosity tests. Meanwhile, by analyzing the heating system, characteristics of heating system are high lag, inertia and nonlinear system, and heating resistor wire——Silicon molybdenum rods can not endure the current break. These factors also hindered the increase of heating rate. Temperature control is the major factor that affects the viscosity testing devices. By analyzing the existed research results, combining heating system features of high-temperature melt viscosity intelligent testing device, a new method is proposed which combines threshold control with adaptive fuzzy PID control. And simulation and experiment results validate the proposed control method.Thirdly, according to the design of the hardware system and temperature control algorithm, the system monitoring and control software is designed. Software design uses the Visual C++6.0 integrated development tools. Interrupt technique and multithreading technique are used in software.Finally, the experiment results the intelligent high-temperature melt viscosity test device fully meet the design requirements.