You can change the number of graphs, and their scaling in Preferences -> Charts.
To add a chart click the plus button, then enter the scale and graduations that you want.
If you want the graph to be displayed on screen click Display Chart.
If you wish it to print, choose Print Chart.
The Size Ratio slider changes the size of the selected graph compared to the other graphs on screen.
The Time Scale slider changes the time scale on the graphs displayed on screen.
