音速喷嘴法气体流量计自动检定系统的设计与实现

摘要

To enhance the calibration precision and efficiency for gas flowmeters, the automatic calibration system for gas flowmeters based on Venturi sonic nozzle using negative pressure method is designed. The operational principle of the sonic nozzle and its device are described, the design scheme of the automatic calibration system is proposed. The operation of the hardware devices is controlled by the program written in VC + + environment of the host computer, to implement automatic control for data acquisition and calibration procedures. After completion of the calibration, the system automatically judges whether the flowmeter is qualified or not, and stores the results into SQL Server database. The practical applications indicate that this automatic calibration system features stable performance, and is helpful to enhance the calibration precision and efficiency for gas flowmeters.%为提高气体流量计的检定精度和效率,设计了一种基于文丘里音速喷嘴的负压法气体流量计自动检定系统.阐述了音速喷嘴及其装置的工作原理,提出了自动检定系统的设计方案.在VC++的环境下编写上位机软件控制硬件设备操作,实现了自动数据采集与检定过程的自动控制,检定完成后由系统自动判定流量计是否合格并把检定结果存入SQL Server数据库.实际应用表明,该自动检定系统性能稳定可靠,且有利于提高气体流量计检定的效率和准确度.