Q. First type of rheological model?

This method establishes relation between the pressure gradient and the volume rate of flow. Here, the piston measurement is used to measure the consistency of the product present in the cylinder. If the load required is more, consistency is thick. It consists of a piston sliding in the cylinder filled with oil as shown in the figure 8.5. Here, the load is connected with piston, as you can see from the figure 8.5, which provides the force for piston movement. If the viscosity is high, more loads is required to obtain a constant movement. Oil can be replaced by the food material for which the measurements are to be taken. The initial period of no deformation is there. The piston starts moving only after a critical load is applied. After sometime, the deformation remains constant. This model can be used only for fluid test products.