Agilent Technologies 4294A Programming Manual page 214

Application Sample Programs
Measuring Magnetic Materials
Step 3. Connect the 16454A
Connect either the small of large electrode of 16454A (whose size is suitable for the shape
of the magnetic material (MUT) you want to measure) to the 42942A.
NOTE
For details on how to handle the 16454A (the dimensions of the MUT suitable for
measurement in each size (small or large)), refer to the 16454A Operation and Service
Manual.
Step 4. Specify the measurement conditions
Specify the measurement conditions including the measurement frequency and the
measurement signal level.
Step 5. Execute fixture compensation
Insert only the MUT holder and perform SHORT compensation
Step 6. Insert the MUT
Insert the MUT with the holder into the 16454A.
Step 7. Execute impedance measurement
Measure the impedance (R + jX).
Step 8. Calculate permeability
Using the following expressions and the result of the impedance measurement, calculate
the complex relative permeability (
MUT.
Equation 13-3 Expressions to calculate the complex relative permeability and the loss tangent
Where,
Zm
f
h
c
b
214
·
· Zm
μ
------------------------------------------------------- -
=
j f μ ( × × × ( c b ⁄
r
h ln
0
X
μ
------------------------------------------------ -
' =
f μ × × ×
r
h
0
μ
''
r
δ
------ -
tan =
μ
'
r
·
μ
Complex relative permeability of MUT
r
·
Impedance (complex number) [Ω]
= R + jX
μ
Permeability of vacuum (=1.257×10-6) [H/m]
0
Frequency [Hz]
Height of MUT [m]
Outside diameter of MUT [m]
Inside diameter of MUT [m]
·
μ μ μ
= -j
'
r r r
X
------------------------------------------------ -
+ 1 =
) ) f μ × × ×
h ln
0
+ 1
( c b ⁄ )
ln
) and the loss tangent (
''
R
------------------------------------------------ -
+ 1 j –
f μ × × ×
( c b ⁄ )
h ln
0
R
μ
------------------------------------------------ -
'' =
f μ × × × ( c b ⁄
r
h ln
0
δ
) of the
tan
( c b ⁄ )
)
13