95x Series Operating Manual - May 17, 2022
Page
80
of
155
LEAD COMPENSATION (4 -WIRE)
Lead Compensation is not usually performed when using a 4-wire measurement since lead resistance is
automatically eliminated. If a 4-wire test is configured but the DUT is connected in a 2-wire manner (e.g., separate
wires for SOURCE and SENSE, but they are shorted together before the connection to the DUT) then a Lead
Compensation may be performed in the same manner as for the 2-wire configuration above.
EXAMPLES
Example 1 -
A DUT has a 50
Ω
input and it is desired to check that the input impedance is within 5% of the nominal 50
Ω
value.
This is accomplished in a single step as follows
–
Seq 1 Step 1 LOW
2/4-WIRE: 2-WIRE
Lead resistance is well below 2.5ohm, so 2-wire is chosen
TIME: 0.10sec
Load has very little capacitance so use a fast time
Delay: 0.00sec
Load has very little capacitance so no delay needed
Lim: 47.50-52.50
As required
ON FAIL: ABORT SEQ
Example 2 -
It is required to test that a DUT chassis is bonded to its grounding terminal with no more than 0.1ohm of
resistance.
This is accomplished in a single step as follows
–
Seq 1 Step 1 LOW
2/4-WIRE: 4-WIRE
Lead resistance is significant, so 4-wire is chosen
TIME: 0.10sec
Load has very little capacitance so use a fast time
Delay: 0.00sec
Load has very little capacitance so no delay needed
Lim: 0u- 100m
As required
ON FAIL: ABORT SEQ
SPECIFICATIONS
Specifications are valid at the 95x terminals for 1 year at ambient temperatures within ±5C of calibration
temperature (add 5% of accuracy specification per C outside of this). All specifications are relative to the
calibration standards used. Add ½ digit to all accuracies for displayed results (results available with enhanced
resolution from interfaces).
TEST CURRENT SOURCE
Test Current
55mAdc max
Opt. LRE-10 : 10mAdc max
Open Circuit Voltage
5V (nominal)
Source Resistance
130
Ω
(nominal)
Opt. LRE-10 : 530
Ω
(nominal)
MEASUREMENT ACCURACY (2-WIRE)
Measurement Period
7.25msec measurement period (100ms for test time >2 sec)
Accuracy
<30K
Ω
: 0.8% + 0.02
Ω
30-100K
Ω
: 1.5%
