The Oil Flow Point Automatic Measuring System Based On AVR Single-chip Microcomputer

With the increase of the consumption of the processed oil, the domestic oil is far from meeting the demand. We have to import large amounts of oil overseas. The oil transportation must be paid much attention to. Keeping the oil liquid is the one of the most important thing during oil transportation throught pipeline which is the low cost and hign proformance.This main task of the design is measuring the oil flow point by means of automation technology and the theory of embedded system. It is designed according to the national standard GB/T3535-83 for flow point and national standard GB/T510-83 for solidfying point. This oil flow point measure system has following features:(1) Use double CPU stucture, communication between them is series communicaion. The weak connect confirms the real-time character of control and improve the reliability of the whole system;(2) Use the high-precision AD converter CS5511 of Cirrus Logic. Its wide dynamic characteristics, programmable output rate and flexible way of power supply make itself being the ideal design scheme;(3) Introduce a new algorithm of temperature adjustment. It sloves effectively the zero drift and amplifier gain drift. The result of temperature satisfies the demand of measuring accuracy.The whole system includes the display terminator, control terminator and the monitor program. The main functions of display terminator are man-machine interaction, displaying the real-time data and modifying the run parameters; the main functions of control terminator are measuring the flow point of oil automatically and responding to the order of display termitor to realize the manual control; the functions of the monitor program are querying state of each knot, modifying the parameter of each kont,display the real-time data of each knot and simulating the measuring process by the way of figure. The hardware design includes display terminator and control terminator's schematic design, PCB design and hardware debugging; the software design includes the coding and debugging of the display program, the control program and the monitor program. The programming languages include assemble language, C language and C++ language.The test data indicate the repetitiveness and reproducibility of oil flow point the system are well, and can offer reliable reference for the transportation of oil. This measuring apparatus can be used all kinds of industrial locale because of its hige precision and high degree of automation. But some of parts of the system can be improved and ameliorated.