The Software And Hardware Design And Realization Of The Rheometer

Polymeric Materials Analyzer -- rheometer is the device that is used to measure fluid properties of polymer. Capillary rheometer can measure the shear stress and shear rate and draw the rmoplastic material stress-strain curve, plastics curve, and the material softening point, melting point, pour point temperature of the polymer melt viscosity and activation of viscous flow. Capillary rheometer can measure the shear stress and shear rate and draw the rmoplastic material stress-strain curve, plastics curves , and the material softening point, melting point, pour point temperature of the polymer melt viscosity and activation of viscous flow.The rheometer changes the temperature on two ways that are constant temperature and rising the temperature with the average speed .When the temperature rises with the average speed, the modality of the material in the sample stove changes, then we could get the point of the temperature in the different modalities .When the temperature librates in the range of setting, we push the material to observe the speed of the material down .So we could get the mechanical characteristic in the condition .In the different condition, we could get the different data ,and get the different curves In the process of quickly heating ,the polymer gradually be heated in the furnace, the state gradually changes, the polymer can be observed at different temperatures in the state, and the material can be measured at the softening point, melting point, pour point. In the process of constantly heating, using extrusion effects observed furnace materials in the decline rate of polymer in the molten state under the shear stress and viscosity, polymeric materials are in a constant temperature of the fluid pressure. In order to be more accurate polymer fluid performance indicators, so the original rheometer and improve the system, the new capillary rheometer is a new control structure, a more accurate and faster data processing and data storage, and use industrial control PID temperature control algorithm, makes temperature control more stable , more efficient.The system of the rheometer is made up of three parts: the sample stove ,the controller ,the PC. The software in PC controls the controller and deals the data from the controller, draws the curves with the data .The controller receives the orders from the PC and controls the temperature in sample stove to do the experiment . The sampling data could be provisional saved before being sent to the PC.The sample stove is the place where do experiments whose characteristics are insulation, well keeping the temperature in the stove and good closedown .The platinum resistance has the function of testing the change of temperature in the stove .And in the stove the warming filament has the function of warming the temperature.In the rheometer system a very important industrial technology ---- the PID arithmetic which is used in the system of controlling the temperature .The controller measures the temperature in time, and controls the temperature with the warming filament .We program to the PID arithmetic to form the system of controlling temperature .Because the temperature reflect the heat ,we could not program the unbroken PID formula .We improve on the formula to save the CPU resource . In this paper, the PID algorithm has been optimized, that is, only the proportion of PID algorithm (P) and integral (I), and in accordance with the formula algorithm controller to adjust the temperature control system and optimization. Based on this formula, we can sample the temperature of the furnace for better control, regardless of the temperature or during heating process,it will have a more ideal temperature curve.Rheometer System Design and Implementation of the hardware part has focused on the controller.The CPU is one part of CS-51.The main control system do many things that getting the temperature,controlling the temperature ,dealing the data in the experiments ,sending the data to PC ,etc .The electrocircuits all round are the getting temperature circuit ,the getting displacement circuit ,the controlling temperature circuit ,the transmitting data in series circuit ,etc .The getting temperature circuit and the getting displacement circuit have the main target on converting from analog to digital .Temperature in the acquisition circuit through the platinum resistance to the acquisition by the voltage value, the voltage value of the input given by ICL7135.The software is designed in the two parts of the controller and the PC .In the controller ,the program contains many parts ,such as the main control part ,the getting temperature part ,the getting displacement part ,the controlling temperature part ,the data transmission part ,etc .Each program part in the controller is corresponding with the each circuit in the controller .And the main part is the leader for the other parts .In PC ,the program contains two parts :the data transmission part and the image show part .The data transmission part links both the controller and the PC . Data processing is to get the data from the controller to deal with the formula by shear rate, the apparent shear stress, the apparent viscosity of the chemical professional useful data.And the image show part shows the smooth curve to the user.This paper presents the designed and realization of a type of Macromolecule Analyse ---- the rheometer in the software and the hardware parts .Now the system has nearly completed ,and the system is debugging .And the performance reaches the anticipated the designed objectives nearly . Maybe many problems may appear, and those are our future issues.