Capillary rheometer is a kind of poiseuille flow based viscosity measurement equipment. Compared with rotational parallel-plate rheometer, capillary rheometer is considered a better way to determine the viscosity over a large range of and process-related shear rates. The measuring principle of capillary rheometer requires different corrections to get accurate apparent shear rate and shear stress in non-newtonian fluids testing. In this study, a lab-made capillary magneto-rheometer was developed for measuring viscosity of Magneto-rheological fluids over a wide range of shear rates (10¹~10⁵ 1/s). The Rabinowitch correction and Bagley correction are applied and verificated by simulations for the obtaining accurate apperent shear rates and entrance pressure drops. The rheological properties of MRFs with different particle volume fractions（10%、15%、20%）and stimulated with different magnetic field strengths（6mT、13mT、20mT、25mT）were tested and analyzed，the rheological characteristic curves of MRFs with shear rate range of  were obtained and the normalized characterization using Mason number were conducted.
 

Magnetorheological Fluids；Capillary Magneto-rheometer； High Shear Rate； Viscosity； Mason Number.