Agilent Technologies 4294A Programming Manual page 192

Application Sample Programs
Measuring Dielectric Material
Step 7. Insert the MUT
Insert the MUT between the 16451B's electrodes.
Step 8. Cp-D measurement
Measure the equivalent parallel capacitance (Cp) and the dissipation factor (D). When
using the non-contacting electrode method, perform the Cp-D measurement twice in this
step: one with the MUT connected and the other not connected.
Step 9. Calculate permittivity
Using the following expressions and the result of the impedance measurement, calculate
the complex relative permittivity (
of the MUT.
Equation 13-1 Expressions to calculate the complex relative permittivity (each term) and the
dielectric dissipation factor when using the contacting electrode method
Equation 13-2 Expressions to calculate the complex relative permittivity (each term) and the
dielectric dissipation factor when using the non-contacting electrode method
Where,
ε0
Cp
Cp1
Cp2
D
D1
D2
ta
tg
d
π
192
×
t Cp
a
ε
------------------------------------- -
' =
r
2
π × ( d 2 ⁄ ) × ε
0
=
D D
t
1
ε
------------------------------------------- -
' =
r
Cp t
 
1 g
×
--------- --- -
1 – 1 –
 
Cp t
2 a
ε × ( ) ×
D = D + D – D
t 2 r 2 1
Permittivity of vacuum (=8.854×10-12) [F/m]
Measured equivalent parallel capacitance value [F] (contacting
electrode method)
Measured equivalent parallel capacitance value when no MUT is
inserted [F] (non-contacting electrode method)
Measured equivalent parallel capacitance value when an MUT is
inserted [F] (non-contacting electrode method)
Measured dissipation factor value (contacting electrode method)
Measured dissipation factor value when no MUT is inserted
(non-contacting electrode method)
Measured dissipation factor value when an MUT is inserted
(non-contacting electrode method)
Thickness of MUT [m]
Distance between the guarded and unguarded electrodes [m]
Electrode diameter [m]
Pi (circular constant)
·
ε ε ε
= -j ) and the dielectric dissipation factor (Dt)
' ''
r r r
ε
''
r
ε
= ------
'
r
D
t
ε
''
r
ε
------
' =
r
D
t
t
 
g
--- - 1
–
 
t
a
13