Any portion of a profile can be magnified for close examination. Using the
procedures of the previous section, position the cursors so that they bracket the
feature of interest. Press the yellow PLOT button. The display will zoom in
on the bracketed region. The horizontal and vertical scales will each auto-range
to provide the greatest magnification that the feature's size will allow.
The cursors will still be located at the same points on the profile after the image
is re-plotted. The profile will be positioned to place the left cursor at
the left edge of the screen. The right cursor will appear in the right half of the
screen after the zoom.
To return to the previous magnification after zooming, press PLOT again without
moving the cursors. the cursors will remain in their most recent position.
Pressing PLOT again will not cause zooming until a cursor has been moved.
To return to the screen showing the entire profile, press ABT. This undoes all
zooming, but leaves the cursors at their most recent positions on the profile.
Pressing CUR then ABT undoes all zooming and returns the cursors to the ends
of the scan.
4.5. Average Difference Mode
In Average Difference mode, the system computes the difference between
average height measurements. When this mode is entered the currently displayed
average is stored as a reference reading. The instrument displays the
difference between this reference and all subsequent average height
measurements. This mode remains in effect until it is exited, even if another
scan is taken.
1. Level the plot if necessary (see Section 4.3).
2. Position the measurement cursors on the section of the profile to be stored as
the reference reading.
3. Press ENT, then the "dot" key [+].
The vertical height field will be re-labeled "dAv" for average difference. It
will read "0" until the cursors are moved.
The difference between cursor heights is not shown in this mode, since the
cursors are typically placed at the same profile height when an average is being
taken.
