Multiple Curve Analysis enables the evaluation of multiple force plots.
MCA Procedure
Two windows will open:
- An image similar that shown in Figure 1, with the curve points highlighted.
- An MCA window, similar to that shown in Figure 2
Click Add Files in the MCA window to open a file selection window and click the files to be analyzed. Choose the preferred files and click Add. These files are then added to the file list in the MCA File Information Register. Files in that list may be removed individually or multiply by clicking the file name and then clicking Remove Files.
Figure 2: Multiple Curve Analysis Window
MCA Interface
Table 1: Image Cursor Mode Selections & Buttons
| Parameter | Description |
|---|---|
| Select Box | |
| Unselect Box | |
| Measure Line | |
| Check All | |
| Uncheck All |
Table 2: MCA Parameters
| Parameter | Description |
|---|---|
| Display: | |
| Plot Units | The user can choose either Force, Volt or distance (Metric) on the Y axis. |
| Direction | The Extend option plots and looks for peaks only in the Extend direction. The Retract option plots and looks for peaks only in the Retract direction. |
| Type | Either Z or Separation. Z displays the Z position of the piezo measured by a capacitive sensor. Separation displays the corrected (for cantilever deflection) Z data. |
| Invert | The Y axis is inverted when Yes is selected. |
| Plot | Any of three channels may be plotted. |
| SelectMode | On turns all curves to color number one and the selected (by mouse or arrow key) curve to its plot color. |
| Peak Detection: | |
| Minimum size | Finds peaks greater than the value entered here. |
| Percentage of Max | The Y variable must fall by this percentage to be considered a peak. |
| Minimum Width at % Max | A peak must have a width (at Percentage of Max of the peak’s absolute value) greater than the Minimum Width at % Max to be considered a peak. |
| Auto Align Curves: | |
| X-axis auto-zero | Either On (at the contact point), Off or User. |
| Y-axis auto-zero | Either On, Off, User or Cascade which increments the Y offset of each plot by the Cascade Offset. |
| Cascade Offset | Define the Y offset to be used here when the Y Axis Autozero is set to Cascade. |
Table 3: MCA File Information Register
| Parameter | Description |
|---|---|
| Add Files | Opens a file selection window that allows files to be added in the Multiple Force window. |
| Remove Files | Deletes selected (by clicking) files from the Multiple Force window |
| Find Peaks | Finds peaks using the filters (rules) selected in the Peak Detection functions to the right of the plot window. The X Offset and Y Offset, Peak Number, X Value, Y Value, Peak-To-Peak and DY Values are shown in the table below the plot window, as shown in Figure 9.4e. |
| Refresh Plot | Used to refresh the plot window after selecting or deselecting files or changing inputs. |
| Export | Saves the results from Find Peaks in a tab-delimited text file. |