Petroleum Products Pour Point Measuring System Based On ARM Microprocessor

As the production of petroleum ranking top all over the world, it becomes research hotspot that how to realize the low consumption and low expenses pipeline transportation of petroleum. The fluidity is an important factor that influences the pipeline transportation of petroleum, especially in the region which temperature is low because of the low temperature will decrease the fluidity of petroleum, or even lose the fluidity. And this case is very harmful for the transportation of petroleum. As an important evaluation indicator, pour point of petroleum should be measured to improve the technology of pipeline transportation and to reduce the expenses of transportation and consumption. A high-accuracy automatic petroleum pour point measure system is designed based on domestic standard and overseas standard.Through the comparison of many standards for measuring pour point, the automatic air pressure method was used to measure pour point of petroleum in this paper. ARM was used to control the system as core of the hardware. And the semiconductor chilling plate is used to cool the sample, while the platinum resistance thermometer was used to detect the temperature of the sample and the temperature control block. Stepping motor is controlled to driving the air source tube to pressurize on the sample, and the pressure was detected by the micro pressure sensor to judge whether the petroleum lost fluidity. This method has good repeatability and reproducibility. and it is easy to realize automation.The STM32F107VC, which has the ARM Cortex-M3as the core, with characteristics of high-performance, real-time, low power consumption and low voltage and so on, was used in this system as the core of the whole hardware. The microprocessor is used to produce PWM wave which can control the heating time combined with photoelectric coupler and SCR so that the system can be controlled to the preset temperature and the cooling rate. This system has so rich channels for man-machine interaction that it is more convenient to operate and to monitor the system real-time, and to print the result. The anti-interference measurement is used to ensure the reliability and stability and to improve the ability to prevent the interference in both hardware and software aspects. And the PID control was used to control temperature and ensure good efficient of closed-loop control. In the meanwhile, modular programming which has good portability and high efficiency helped to debug easily...