摘  要

计量是工业生产的眼睛。流量计量是计量科学技术的组成部分之一，它与国民经济有着密切的关系。尤其在当今能源危机，工业生产自动化越来越高，能源使用浪费现象严重的时代情况下。流量计有了越来越重要的地位，受到人们越来越多的关注。在当今社会流量计已经广泛运用于工农业生产，交通运输，国防建设，科学研究，对外贸易，以及人民生活的各个角落，由此可见对流量计的研究与开发认知，有着广泛的意义和作用！

根据实现功能的需要，本课题设计了一款基于AT89C51为核心的罗茨气体流量计。该流量计具有测量精度高，能耗低，稳定性好，测量范围广，维修方便等优势。控制器主芯片AT89C51具有低功耗，驱动能力强，稳定性好等特点。根据设计要求硬件部分主要分四个模块，即流量传感变送模块，主控CPU智能模块，LED数码管显示模块和上位机通讯模块。各模块能独立工作，并通过通讯接口，键盘模块等功能模块组成功能完善的整体。流量计的设计结构合理，运行稳定可靠，同时具有了RS-485通信接口，适合应用于远程分布式系统的流量检测

关键词：罗茨气体流量传感器；AT89C51芯片；RS-485通讯接口

ABSTRACT

Measurement is the eye of industrial production. Flow measurement is one of the components of metrological science and technology, which is closely related to the national economy. Especially in today's energy crisis, industrial production automation is getting higher and higher, energy waste is serious. Flowmeter has become more and more important and has attracted more and more attention. In today's social Flowmeter has been widely used in industrial and agricultural production, transportation, national defense construction, scientific research, foreign trade, as well as every corner of people's life, it can be seen that the research and development of Flowmeter has a wide range of significance and role!

According to the need of realizing function, a Roots gas Flowmeter based on AT89C51 is designed in this paper. The Flowmeter has the advantages of high measurement accuracy, low energy consumption, good stability, wide measurement range, convenient maintenance and so on. The main chip AT89C51 of the controller has the characteristics of low power consumption, strong driving ability and good stability. According to the design requirements, the hardware is mainly divided into four modules, namely, flow sensing transmission module, main control CPU intelligent module, LED digital tube display module and upper computer communication module. Each module can work independently, and through the communication interface, keyboard module and other functional modules to form a fully functional whole . The design structure of Flowmeter is reasonable, the operation is stable and reliable, and it has RS-485 communication interface, which is suitable for traffic detection of remote distributed system.

Key words: Roots gas flow sensor; AT89C51 chip; RS-485 communication interface