Viscosity Correction Factor for Rotameter

Abstract

This paper describes how the developed formula for rotameter flow coefficient using the rotameter scale provided by a manufacturer and valid for a specific fluid and for design (or calibration) flow conditions allow us to determine the actual flow rate at measurement conditions and for different fluid having different viscosity or allow us to determine the viscosity correction factor. The developed theory has been verified experimentally using typical rotameter equipped with the plumb type float, for water of 15°C and having a flow rate range from 10 to 100 l/hr. A very good agreement between theoretical calculation and calibration results was obtain for water flow at 88°C. In this case the kinematic viscosity ratio was v 15 /v 88 = 3.46 and the density correction factor was Fdens = 1.019 and the viscosity correction factor varied from Fvisc = 1.095 at 100 l/hr to Fvisc = 1.93 at 10 l/hr.