.

This PDE can be transformed into a system of ODEs by finite differencing the reactor length into equally sized segments of length .

The Péclet number is given by , where is the effective axial diffusivity, the reactor length, and the velocity. This dimensionless number appears naturally and is a measure of convection versus dispersion effects.

If the reaction rate constant is set to 0 it is possible to get the -curve, by using the pulse inlet concentration, for various values of the Péclet number, . It is observed that there is large dispersion when the number is small, which corresponds to large values of the axial diffusivity.