Model 4342A
Section III
Paragraphs 3-24 to 3-29
to measure with either connection method.
These limits are based on the use of a ref-
erence inductor having a Q value of 280.
Parallel measurement low limits can be ex-
tended by using an external capacitor con-
nected to the measurement CAPACITOR (HI and
GND)
terminals.
3-24. High Q Measurement.
3-25. Measurement of high quality factors up
to 10000 can also be made by the parallel or
series connection methods. These methods
enable the measurement of low loss samples
and are especially useful in the measurement
of high Q capacitors.
As
inherent losses in
the instrument will cause larger incremental
measurement errors in higher Q measurements,
these residual loss factors should be taken
into consideration in the accuracies of meas-
ured values. In high Q measurements, the
measured Q should be deemed to be only a
rough approximation of the sample Q value.
A
detailed discussion on parallel and series
connection measurement errors is provided in
paragraph 3-60 and those which follow.
IOK 22K IOOK IM IOM 70M
MEASURING FREQUENCY IN Hz
Figure 3-5.
Ranges of Measurable Resistance.
3-26.
Supplemental Equipment Used in
Parallel and Series Methods.
3-27. For use with the 4342A as reference
inductors, the Model 16470A series supple-
mental inductors are available. The
16470A
series inductors have various inductances
(from 0.07pH to 630mH) and totally cover the
frequency range of 1OkHz to 70MHz when used
with the 4342A as measurement aids. The ref-
erence inductor must be resonated alone
(before connecting unknown) at the desired
measurement frequency to take its inherent
values for reference. And, of course, the
useable frequency range of each individual
supplemental inductor depends upon the in-
ductance of the individual coil. This fre-
quency range is indicated on a label attached
to the case of each inductor. Detailed data
and information on the supplemental inductors
is tabulated in Table 1-2.
3-28. Inductor samples whose inductance is
somewhat lower than the low limits of the
measurement range of the 4342A may be meas-
ured by using an external high Q capacitor to
extend the available tuning capacitance range.
The external capacitor is connected between
HI and GND measurement terminals; its capaci-
tance, thereby, adds to the tuning capaci-
tance. For this special purpose, the HP
16462A Auxiliary Capacitor is available.
This capacitor module combines nine capaci-
tors from 300pF to 2700pF (in 300pF steps) and,
when used with the 4342A, allows measurement
of low inductances to approximately l/6.7 of
the measurement
low limit
of the instrument.
3-29.
Dielectric constant of an insulating
material is calculated from the capacitance
value of the sample held between a pair of
electrodes whose dimensions are accurately
known. Model 16451A Dielectric Test Adapter
is the test fixture which is specially de-
signed for measuring dielectric constant
(E)
and dielectric loss angle (tan 6) and is di-
rectly attached to the 4342A measurement
terminals. The 16451A has a pair of variable
precision electrodes which can hold materials
measuring up to a maximum of 1Omm in thick-
ness. The electrodes operate similar to a
micrometer permitting direct reading of elec-
trode spacing (0 to 1Omm) with 0.02mm resolu-
tion.
The diameter of the electrodes has
been designed so as to simplify the associat-
ed calculations. Measurement time is thus
greatly shortened.
3-7
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