Vortex flowmeter,as a flow meter widely used in industrial field,can measure the flow of gas and liquid.Compared with other flowmeters,it has a wider scope of application.The accuracy of Vortex flowmeter is higher from 0.5 to 2 level.So it is possible to use some flowmeters even if they have measurement requirements.The working conditions of Vortex flowmeter should be clear,and each working condition is right.The realization of accuracy is also different.

 

　　渦街流量計(jì)的精確度

　　Accuracy of Vortex Flowmeter

 

　　渦街流量計(jì)的精確度對于液體大致在±0.5%R～±2%R，對于氣體在±l%R～±2%R，重復(fù)性一般為0.2%～0.5%。由于渦街流量計(jì)的儀表系數(shù)較低，頻率分辨率低，口徑愈大愈低，故儀表口徑不宜過大（DN300以下）。

 

　　The accuracy of the vortex flowmeter is about(+)0.5%R to(+)2%R for liquid and(+)l%R to(+)2%R for gas.The repeatability of the vortex flowmeter is generally 0.2%-0.5%.Because the instrument coefficient of vortex flowmeter is low,the frequency resolution is low and the caliber is larger and lower,the caliber of instrument should not be too large(below DN300).

 

　　范圍度寬是渦街流量計(jì)的特點(diǎn)，但重要的是下限流量為多少。一般液體平均流速下限為0.5m/s，氣體為4～5m／s。渦街流量計(jì)的正常流量最好在正常測量范圍的1/2～2/3處

 

　　Wide range is the characteristic of vortex flowmeter,but what matters is the lower limit flow rate.The lower limit of average liquid velocity is 0.5m/s and gas velocity is 4-5m/s.The normal flow rate of vortex flowmeter should be 1/2-2/3 of the normal measurement range.

 

　　適用的情況

　　Applicable circumstances

 

　　渦街流量計(jì)不適用于測量低雷諾數(shù)（ReD≤2×104）流體。低雷諾數(shù)時斯特勞哈爾數(shù)隨著雷諾數(shù)而變，儀表線性度變差，流體粘度高會顯著影響甚至阻礙旋渦的產(chǎn)生，選型的一個限制條件是不能使用于界限雷諾數(shù)之下。渦街流量計(jì)適用的流體比較廣泛，但對于流體的臟污性質(zhì)要注意。含固體微粒的流體對旋渦發(fā)生體的沖刷會產(chǎn)生噪聲，磨損旋渦發(fā)生體。若含有的短纖維纏繞在旋渦發(fā)生體上將改變儀表系數(shù)。

 

　　Vortex flowmeter is not suitable for measuring low Reynolds number(ReD<2*104)fluid.When Reynolds number is low,Strauhal number varies with Reynolds number,instrumentation linearity becomes worse,and high fluid viscosity will significantly affect or even hinder the generation of vortices.One of the limitations of type selection is that it can not be used under the bounded Reynolds number.Vortex flowmeters are widely used for fluids,but attention should be paid to the fouling properties of fluids.The fluids containing solid particles will produce noise and wear whirlpool when they scour the whirlpool.The instrument coefficients will be changed if the short fibers are wound around the vortex generator.

 

PS：天津壓力表變送器,渦街流量計(jì)的精度有多少？

PS:Tianjin pressure gauge transmitter,what is the accuracy of vortex flowmeter?