The upper graph is the Tuning Curve, which graphs the TCurve offsets from the main tuning page. If any notes have a custom offset, that offset will appear as a red mark above or below the tuning curve.  If you select the zoom mode with the button shown here, then you can scroll and two-finger pinch-zoom the tuning curve graph.  In this mode, you can double-tap the graph to set the zoom and scrolling to exactly contain the extent of the graph data. Double-tap the zoom button itself to switch between displaying the normal tuning curve with partials and the tuning curve for just the fundamentals. This is useful in manually adjusting a tuning curve to match custom offsets that were set aurally.   If you select the detail mode with the button shown here, then you can view the offset and partial selection for any note.  Just  swipe across the graph until you get the note you want.  The graph is drawn with white and black notes to make this easier.  If you select the adjust mode using the button shown here, then you can adjust the tuning curve.  Double-tap the adjust button to select one of three adjustment modes.  Full automatic mode adjusts with a single tap anywhere in the graph.  Semi-automatic mode lets you adjust the bass and treble shape, but the overall stretch at A0 and C8 is determined by the selected intervals (described later).  Full manual mode adjusts the bass and treble shape and overall stretch.  In either of the manual adjustment modes, a green column will appear in the graph showing where you can adjust by swiping up or down in that column.

The interval select button shown here allows you to select the bass and treble intervals used to draw the Deviation Curve, which is the lower graph.  The interval selection also affects the automatic and semi-automatic adjustments to the tuning curve.  You can scroll and two-finger zoom the Deviation Curve at any time.  Double-tap the Deviation Curve graph to scale the graph to exactly contain all the data.  Double-tap the graph again to force the scaling to +/- one cent.

If a vertical line appears in the Tuning Curve and the Deviation curve as shown here, then it indicates a Split-Scale tuning is in effect. See the User's Manual for more information on Split-Scale tunings. Split-Scale tunings are defined by having inharmonicity measurements for two adjacent notes, which are on either side of the break.

The Deviation Curve normally shows cents. But it can also show beats. To switch to or from beats, swipe the Deviation Curve with a "Z-shaped" gesture that starts near the left edge, moves to the right edge, then back to the left edge, and finally back to the right edge. Then lift your finger. The background of the Deviation Curve will be reddish in color when beats are being displayed.

For more information on methods of adjusting the tuning curve, see the User's Manual, available from our web site:

  tunelab-world.com/pianotuner