Hioki DSM-8104, Instruction Manual

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6.3.2 Measurement by electrode for surface resistance measurement
This electrode is used as a measuring terminal by pressing it onto a surface of the
sample. It can be used simply when a sample is relatively soft.
Strictly speaking, this electrode does not separate volume resistivity strictly. However,
in general, surface resistance is lower and can be measured in practice. It is especially
convenient in measuring samples whose surfaces are treated for prevention of
electrostatic resistance.
Set the measuring mode to “resistance measurement.”
6.3.3 Measurement by electrode for planar sample
Insulation resistance is divided into volume resistance and surface resistance and
characters of them are different. Therefore, volume resistance and surface resistance
must be measured separately.
When insulation resistances of insulating materials are mutually compared, insulation
resistances unique to insulating materials that are not affected by terminal shape or other
factors are needed. These are volume resistivity and surface resistivity and must be
converted by multiplying volume resistance and surface resistance, which are separately
measured, by a constant determined by the dimensions of an electrode used or other
parameters.
(1) Volume resistivity and surface resistivity
An example of electrode to measure volume resistance and surface resistance
and of usage are illustrated in Fig. 6.5.
Usages of electrodes suiting
measurement objects are as
follows.
Ａ
Ｂ
Sample d2
d1
t The main electrode is connected to
the “INPUT” terminal, while the
guard electrode is connected to the
“GUARD” terminal and pair
electrode is connected to the
“OUTPUT” terminal.
Fig. 6.5 Example of Planar Sample Electrode
Volume
resistance
Surface
resistance
A Main
electrode
Main
electrode
B Guard
electrode
Pair
electrode
C Pair
electrode
Guard
electrode