Theory overview of flow measurement using …（流量测量的理论概述使用u2026）.pdf

Theory overview of flow measurement using differential pressure devices based on ISO-5167 standard. Arian FL40 flow computer description. Flow Cad software users manual. ____________________________________________________________________________ Technical note 12, Differential pressure mass flow meter, rev. b, www.arian.cl 1 Introduction 3 1.0 Basic theory4 1.1 Origin of differential pressure flow measurements4 1.2 ISO-5167 standard and its mass flow rate formula7 2.0 The FL40 flow computer10 3.0 Arian ISO-5167 Flow Cad software. 11 3.1 Software Installation11 3.2 Start up. 12 3.3 Fluid selection. 14 3.4 Primary device. 18 3.5 Flow conditions set up. 20 3.6 Calculating results22 3.7 Instrument parameters25 References27 ____________________________________________________________________________ Technical note 12, Differential pressure mass flow meter, rev. b, www.arian.cl 2 Introduction Differential pressure flow measurement is old and reliable. With the aid of microprocessor technology now discharge coefficient calculations can be done in real time. Even more, properties of the fluid can be stored on the instrument and measuring temperature and absolute pressure allows to correct fluid parameters such as density and viscosity and then to obtain the mass flow rate. This are called multivariable mass flow meters. By other side years of research and experiments had been done obtaining better characterization of typical differential pressure devices (nozzles, orifice plate , etc). The ISO5167 standard condenses all this experimental information giving the formulas and procedures for manufacturing a differential pressure flow measurement device of the standard types with a predictable uncertainty.