A set of such curves calculated using equation (23) is shown in Figure 5.

Figure 5. Graph Showing the Change in Velocity Along a Column for Different Inlet/Outlet Pressure Ratios

Figure 5 shows that the mobile phase velocity increases very rapidly towards the end of the column, even at an inlet/outlet pressure ratio of only two. At inlet/outlet pressures of 10 and 15, the mobile phase acceleration is very great indeed. At an inlet/outlet pressure ratio of 15, the mobile phase velocity increases by over an order of magnitude in the last 15% of the column length.