The Research And Development On Heat Quantity Measuring Apparatus Based On Quartz Crystal

With the rapid development of science and economy, the quantity demanded for energy sources will increase quickly in our country. The coal is considered to be one of the most important energy sources, which results into higher requirement for the quality of coal. The calorific value produced by coal is the main standard of the quality of coal, but at present the equipments measuring the quantity of heat can not satisfy the need of society, so it is impendent to make a system with a good accuracy and real-time performance.Firstly, the paper expounds the importance, the status in quo, the level and the aim of research.Then the paper summarizes the system of measuring calorific value.Secondly, the paper presents the basic principle of measuring ,methods, process and formula to be used ,then illuminate the functions of system and the principle of design. We make a scheme of the structure of the whole system, then expound the basic principle of the quartz-crystal sensor to measure the temperature and design the circuit of the quartz-crystal sensor. The method of curve fitting is put forward to solve the coefficient of frequency characteristic of the quartz-crystal sensor.To solve the coefficient correctly we collect lots of data and program in C. Furthermore ,the system often works in the environment with interference ,so by applying the digital filtering we improve the capacity of anti-jamming of the system.Thirdly, by analyzing the characteristic of serial communication in Windows and comparing the functions of methods of serial communication, we adopt the method based on API. A protocol based on serial communication between PC and singlechip is made on the ground of the requirement of research. A thread and class programmed with VC++ is respectively defined in order to collect data. The paper expounds the scheme based on multithreading to improve the real-time performance of the system .We introduce ODBC briefly and construct database to save the data . To be convenient for users we apply a technology that loads dynamic data source.Finally, we validate the functions and evaluate the performance of the system .The results prove the system has a better real-time performance, a better accuracy and precision than the previous system.