Figure 3-4: Open And Short Measurements With Gr874 Connectors; Figure 3-5: Chip Component Tweezers - IET Labs, Inc. RLC Digibridge 1693 User And Service Manual

1693 RLC Digibridge
1689-9602 and 1689-9602-2 bnc-to-bnc Cables
with bnc-T and GR874 Connectors
Open and short should be performed as shown in
Figure 3-4 below when using bnc-to-bnc cables with
bnc-T connectors and the GR874 adapters. During
short connection connect the two GR874 connectors
together. During open compensation spacing similar
to the DUT or at least 0.75" should be maintained to
minimize capacitance between the GR874 connectors.
Geometry:
If is important to maintain the spacing between the
leads during the open compensation at exactly the
same distance as the spacing is when the banana plugs
are connected to the DUT. If the spacing is not exactly
the same there will be an error in the measured value.
This is due to the fact that the four terminal Kelvin
connection stops at the connection between Drive
and Sense. The banana plugs are two-terminal so the
capacitance between the parallel spaced banana plugs
will be measured as part of the overall measurement
unless open compensation is performed to eliminate
this additional capacitance.
Open Connection
Short Connection
Figure 3-4: Open and short measurements with
GR874 connectors
16
7000-05 Tweezers
The small amounts of residual-tip resistance and
inductance can be automatically corrected by using
the Digibridge shorting function with the tips pressed
together. Guard shields between the tweezer blades
minimize capacitance between them. A correction for
this small capacitance can be made using Digibridge
open circuit test with the tips held at a spacing equal
to that of the component's contact spacing.
Measurement accuracy is very sensitive to connection
geometry. The same connection geometry must be
used for open/short compensation as for connection
to the device under test.

Figure 3-5: Chip component tweezers

1689-9600 Test Fixture
Ideally zeroing with the 1689-9600 should be per-
formed with the 1689-9604 Digibridge Calibration
kit.
The alternate method for performing open and short
using two 18 AWG bus wires for the open and one
loop of 18 AWG bus wire for a short. Two wires
should be used to perform an open to ensure that the
pairs of contacts in the 1689-9600 are connected. See
Figure 3-6 below.
Operation