Download Using the Tester

4-Wire Kelvin
The 1100R+ can be used to perform 4-Wire Kelvin resistance measurements. This capability
allows you to null out fixturing resistance and measure very low resistances (down to .001 Ω).
The standard 2-wire resistance measurement requires a single test point for every connection
on the device-under-test. The 4-wire measurement requires two correctly paired test points for
every connection. One test point supplies current (typically referred to as “force”), while the
other senses voltage (typically referred to as “sense”).
You may connect force to sense on the contact mechanism to the device-under-test and see a
very small interface resistance. However, if you bring force and sense together directly on the
contact of the device-under-test, you will eliminate all sources of interface resistance. This extra
effort may not be feasible. For more information, see Four Wire Kelvin Testing at
http://www.cirris.com/testing/resistance/fourwire.html.
Note: 2-wire and 4-wire testing can be put into any combination on the 1100R+ tester.
Building 4-Wire Fixturing
For the purpose of 4-wire testing, the 1100R+
test points are considered either Type 1 (T1) or
Type 2 (T2) points. Each 4-wire pair from the
tester must have one of each point. The tester
uses T1 points as either force or sense; it uses
T2 points as the compliment. While you can
use any standard adapter to run 4-wire fixturing
from the tester, Cirris suggests using one of
the Cirris AHED series adapters. The AHED
adapters map T1 and T2 points in a uniform
alternating pattern as shown on the next page.
The probe can also be used to identify T1 and
T2 points as described further in this section.
The 1100R+ tester must learn a 4-wire fixture. When the fixture is learned, the first-scanned
point of each 4-wire pair becomes the visible point in the Net List. Both test points are listed
below the Net List in the 4W-Wire Kelvin Pairs.
Component
Setting & Test
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