Keithley 8009, Инструкция по эксплуатации

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By using the calculated values for A, volume resistivity (Equation 1) looks like
this:
or
Where: t
c
is the average thickness of the sample in centimeters.
t
i
is the average thickness of the sample in inches.
Volume resistance (R) is derived by dividing the applied test voltage (V) by the
subsequent measured current (I). By substituting R with V/I, the following equa-
tions that are used in Section 2 to calculate volume resistivity are realized:
or
The ASTM standard states that surface resistivity ( σ ) shall be calculated as
follows:
(Equation 3)
Where: R is the surface resistance in ohms.
g is 0.125 inches. This is the distance between the guarded electrode and
the ring electrode (see Figure 3-4).
P is the effective perimeter of the guarded electrode for the particular
electrode arrangement employed.
the guarded electrode (see Figure
-
(V) by the sub-
uation
ρ
22.9
t
c
----------R =
ρ
3.55
t
i
----------R =
ρ
22.9V
t
c
I
---------------ohm-centimeter =
ρ
3.55V
t
i
I
---------------ohm-inches =
σ
P
g
---R =
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