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m. Advance the CAPACITANCE control to the capacitance value derived in
Step I, above.
(For the 60.31 pF upper limit in the Step 1 example, the MULTIPLY C switch
would be in the 0.1 position and the CAPACITANCE control would be advanced
to 600 on the upper dial and to 3.1 on the lower dial.
If the lower limit were
required, the CAPACITANCE control would be advanced to 600 on the upper
dial and 66.6 on the lower dial.)
n. The Model 75D now is programmed to perform single-limit, go/no-go tests.
Sequentially connect the inductive specimens to the test jig, coaxial leads,
or the REMOTE STD coaxial connectors, as applicable, and observe the
NULL INDICATOR meter.
(1)
Upper-Limit Test.
For a go result, the meter must indicate in
the HI sector of the meteFscale.
Midscale is the absolute
upper limit.
If the meter indicates in the LO sector of the scale,
the specimen is higher in inductance than the upper limit, and
the test result is no-go.
(2)
Lower-Limit Test.
For a go result, the meter must indicate in the LO
sector of the meter scale7-Midscale is the absolute lower limit.
If
the meter indicates in the HI sector of the scale, the specimen is
lower in inductance than the lower limit, and the test result is no-go.
NOTE:
Because inductance is a reciprocal function of capacitance, the
HI and LO indications for the Step n tests, above, are the reverse
of those obtained during the corresponding tests of capacitive
specimens in Step m of paragraph 3.1.2.
PART V,
DIFFERENTIAL MEASUREMENTS
3.9
GENERAL.
Follow the applicable procedure to measure the differential of
capacitive or inductive specimens.
Procedures are given for both the amplitude mode
and the phase mode.
Differential measurements may be performed in either mode;
however, use of the phase mode provides a meter sensitivity increase of 10, or 20 dB.
When reading values on the CAPACITANCE dial, apply the MULTIPLY C factor to the
reading.
3.9.1
MEASURING DIFFERENTIAL CAPACITANCE IN THE AMPLITUDE MODE
a. Check that the initial settings on the front panel of the Model 75D are in
accordance with Table 4.
75 D
b-370
35
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