... be used in the fields of air,natural gas and gas to be measuredFEATURES:1.low pressure loss2.Hi-accuracy popularly:±1 ... .0%,special calibrated::±0.5%3.Low velocity min.velocity of ... ,40,50,80,100,150,200,250,300mm.Specification: DN(mm)Normal Flow Range(Nm3/h)PN(mPa)Pressure loss(kPa)Error ...