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MODEL 09-0101: 1-POINT PEN PROBE
Volume Resistance Measurement for Planar materials
Introduction:
Volume resistance measurements determine if the
material has electrical conducting properties through the
bulk of the sample. This test will measure resistance from
top surface to bottom surface of the sample. There are
several possible current paths that the user should
understand and determine which one or combinations of
which give the final reading as shown on the schematic
below by Ben Baumgartner (ESDiscovery 2000).
As shown above, the test current can go along the top
surface, around the edges, through the bulk material at
various points, within the material or across the bottom
surface before reaching the bottom probe.
To ensure that the edges do not contribute to the reading,
it is best to cut the sample into one smaller piece so that
none of the outside vertical edges exists. In this way, the
only way the current can flow is down, not going around
along the surfaces.