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当前，现场采用的天然气标准孔板为一次检测装置的流量测量系统，其主要为机械式和电动单元组合式仪表流量测量系统两种类型。前者系由感测元件因变形产生位移，通过机械杠杆放大驱动记录笔运动，记录纸则采用钟表机构驱动；后者的流量计量系统则根据不同要求进行组合，通常仪表为差压、压力、温度变送器和记录仪表，或采用计算机进行压力、温度自动补偿和进行压力、温度、密度全补偿的智能流量仪，以及由此派生的其他测量系统。同时还介绍了这些系统的仪表流程图、主要构成和优缺点。最后指出了计量仪表需要认可和定期送检。

NATURAL GAS FLOW MEASURING SYSTEM

At present,the natural gas standard orifice plate adoped on the spot is the flowing measuring system with primary monitoring unit which is made by two main kinds of mechanical and electro element combination patterns.The displacement of the former is caused by the deformation of induction element,the movement of recording pen is made by the lever,and the record sheet is driven by clock installation.The flow measuring system of the latter is composed on the basis of various requirements,usually taking primary instruments as the essencial safety pressure differential gauge,pressure gauge and temperature recorder,adopting computer automatically compensating pressure amd temperature and as intelligent flowmeters of pressure,temperature and density full compensation as well as the other survey system derived from the system.The flow sheets,main structures, merits and demerits of the instruments are introduced.