IET Labs, Inc. RLC Digibridge 1693, User And Service Manual, Page: 43 / 171

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1693 RLC Digibridge
Operation
This remote test fixture provides that true “Kelvin”
connections are made at the points of contact with the
DUT leads. The recommended cable should be used
(rather than any randomly chosen BNC patch cords)
because the known cable parameters enable you to
make corrections for best accuracy. Install the remote
test fixture as follows.
1. Remove any adaptors, cables, etc, if present,
from the DUT port of the instrument.
2. Connect the BNC cable assembly to the
Digibridge and to the remote test fixture as
indicated in Table 3-1.
Note that red designates leads that may be “hot”. (When
bias is applied, they carry the negative voltage with
respect to ground.)
On 1693
Bias
Polarity Description
1689-9602
Cable
On
1689-9600
IL + Drive - Black Band I+
PL
+ Potential - Black and
White Band
P+
PH
- Pot Red and
White Band
P-
IH - Drive + Red Band I-
Table 3-1: Connection of Remote Test Fixture
to 1693 with 1689-9602 cable.
3. Before making measurements, be sure to re-
peat the zeroing procedure (open circuit and
short circuit), as described in paragraph 3.1.3.
For notes on cable and fixture capacitance and zeroing,
see paragraph 3.1.3, below.
4. If the DUT is a radial-lead component or has
parallel leads at one side, insert them into
the Digibridge remote test-fixture slots as
described below.
The test fixture provides convenient, reliable, guarded
4-terminal connection to any common radial-lead or
axial-lead component part (using adaptors, 1657-
5995). an axial-lead component part. The slots in the
test fixture accommodate wires with diameters from
0.25 mm (.01 in., AWG 30) to 1 mm (.04 in., AWG
18), spaced from 4 to 98 mm apart (0.16 to 3.9 in.)
or equivalent strip conductors. Each “radial” wire
must be at least 4 mm long (0.16 in.). The divider
between the test slots contains a shield , at guard
potential, with its edges semi-exposed. The tapped
holes (6-32 thread) at the left and right ends of the
test fixture are also grounded, to connect the shields
of extender cables.
Figure 3-8: 1689-9600 Remote Test Fixture
3.2.3 Using the Test-Fixture Adaptors
for Axial-Lead DUT
If the DUT is an axial-lead component or has leads
at opposite ends, insert the leads into the test-fixture
adaptor’s slots as shown in Figure 3-9. Install the test-
fixture adaptors as shown below; put one in each slot
of the test fixture, by pushing vertically downward.
Slide the adaptors together or apart so the body of the
DUT will fit easily between them.
Figure 3-9: 1689-9600 Remote Test Fixture with
1657-5995 Test Clips
Note that the contacts inside the adaptor are off center;
be sure to orient the adaptors so the contacts are close
to the body of the DUT, especially if it has short or
fragile leads.
The adaptors accommodate wires with diameters up
to 1.5 mm (.06 in ., AWG 15). The body of the DUT
that will fit between these adaptors can be 80 mm long
and 44 mm diameter (3.1 x 1.7 in.) maximum. Each