© ICSPI Corp. 2007-2021
nGauge AFM User Manual 2.0
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9.1.1.4.
Level
The scan is looking better now but look at the legend on the right. We want a scale where the
bottom of the scan (the troughs/dark regions) is 0 um (and not 3.80 um). We also want to make
sure that all the troughs are 0 and to eliminate any tilt in the X axis.
A good tool to use for this is the Level Data By Fitting a Plane Through Three Points. This tool is
represented by the triangle icon under “Tools”.
To use the plane fit tool, the user clicks on three points that should have the same height and
Gwyddion fits a plane through these three points.
We’re going to place these three points in the troughs of the calibration grating. Since the trough
should have a height of 0, we’re going to select “Set plane to zero”. We’re also going to increase
the size of the averaging radius from 1 px to 10 px.
Steps
1. Click on the Three Point Level tool.
2. Click on three areas that should have the same height in the scan. Place these points
far apart from each other.
3. Increase the averaging radius to 10 px (or more).
4. Select “Set plane to zero.”
5. Click Apply.
