Atec Agilent-16047A - Manual (Page 46)

Compensation and Measurement: There are three measurement methods for the 16451B. They are
the Contacting Electrode Method (used with 16451B's rigid metal electrode, without any electrodes on
the material under test), the Contacting Electrode Method (used with thin film electrodes made on the
material under test), and the Non-Contacting Electrode (Air Gap method). Select the suitable measure-
ment method and the suitable electrode for the material under test according to the following table.
Summary of Measurement Method
Open and short compensations are recommended in combination with the cable length compensation
before measurement. When measuring above 5 MHz with the 4285A or the 4294A*, load compensation
is also recommended. First, set the instrument's cable length compensation function to 1 m. Then, open
and short compensation is performed by using the furnished electrode attachment. Load compensation
is performed, by preparing a working standard. After performing open, short and load compensations,
the MUT is sandwiched by the parallel electrodes and the capacitance is measured. Relative permittivi-
ty is calculated from the measured capacitance in the following manner:
t
a
×
C
p ε r' = ———————
d
π Ч
(—) 2 Ч ε
o 2
ε r' : Relative permittivity
C
p
: Capacitance (measurement data)
ε
o
: 8.854 × 10 –12 [F/m]
t
a
: Average thickness of test material
d : Diameter of guarded electrode
*For more information on load compensation with the 4294A, see section 13 of the 4294A programming
manual.
Up to 110 MHz (4-Terminal Pair) Material
41
Measurement Contacting Electrode Method Contacting Electrode Method Non-contacting Electrode
Method (used with Rigid metal (used with thin film electrode) Method
electrode)
Accuracy Low ············································································································································
→
High
Operation Simple·································································································································· → Complex
Applicable Thick, solid and smooth Materials on which thin film Thick, and soft materials.
Materials materials can be applied without Rough materials also.
changing its characteristics