From the equations above we see that
μp = \(\phi\) 600 – \(\phi\) 300,
μa = \(\frac{\phi 600}{2}\)
Where, μp is the plastic viscosity (Cp), which is the slope of the shear stress (τ) vs. shear rate (γ) curve for both the Bingham and the Newtonian models. μa is the apparent viscosity (Cp), \(\phi\) 600 is the viscometer reading at 600 rpm, \(\phi\) 300 is the viscometer reading at 300 rpm .
The Newtonian curve intercepts at (0, 0) and would have a straight line curve, τ = μp γ while the Bingham curve intercepts at (0, X) and would have a straight line curve, τ = μp γ + X where X is the yield point of the fluid and a point on the Y-axis. A Non-Newtonian fluid lies between the Newtonian and Bingham curves.