ADCMT 12704A - Calculating Volume and Surface Resistivities

A-2
12704A Resistivity Chamber Operation Manual
A.1 How to Calculate Volume and Surface Resistivities
A.1 How to Calculate Volume and Surface Resistivities
Formulas to calculate volume and surface resistivities are described below:
Volume resistivity:
Rv
t
4
d
v
2



------- (1)
Surface resistivity:
Rs
dD
)dD(
s 


 ------- (2)
The electrode diameters of the 12704A are as follows:
Figure A-1 Electrode Diameter
The following formulas are obtained by substituting these values for formulas (1) and (2).
Volume resistivity:
t
Rv
63.19v 
[cm] ------- (3)
Surface resistivity:
Rs84.18s


[] ------- (4)
By substituting measured values for formulas (3) to (4), the volume resistivity and the surface
resistivity can be obtained.

v : volume resistivity [cm]
s : surface resistivity []
Rv : volume resistance []
Rs : surface resistance []
 : circumference ratio=3.14
t : sample thickness [cm]
D : guard electrode inner diameter [cm]
d : main electrode diameter [cm]
Main electrode
Guard electrode
Sample
Opposed electrode
Main electrode diameter: 50 mm
Guard electrode inner diameter: 70 mm
Guard electrode outer diameter: 80 mm
Opposed electrode outer diameter: 83 mm
JIS-K6911 - compliant