Right Y-Axis (Double Y-Axis)


Different columns often give values of widely varying ranges. Fully accommodating one column of data on a graph may result in an indecipherable straight line for the other column. To get a good view of both column plots, despite their varying ranges, you can add a Y-Axis to the right-hand side of the graph. The new Y-Axis will have its own scaling, independent of the scaling of the Y-Axis on the left of the graph.

For example, in a standard acid-base titration experiment, you often cannot get a good view of both the pH and derivative data on a single graph if both columns are sharing the same Y-Axis.

                Columns plotted along the same Y-Axis

A second Y-Axis, however, can be scaled independently than the original Y-Axis. This results in two readable lines on the same graph.

 

                  Columns plotted on different Y-Axes

How to Add a Right Y-Axis

1. Either double-click on the existing graph or choose Graph Options from the Options menu to call up the Graph Options dialog.

2. Click the Axes Options Tab.

3. Check the Right Y-Axis box.

4. Choose a column to plot.

5. Click Done.