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NI 9219 Calibration Procedure
Figure 6.
4-Wire Resistance Accuracy Verification Connections to the NI 9219
2.
Acquire an
Ω
ref
measurement.
a.
Create an AI voltage channel in the 1 V range on the NI 9219.
b.
Commit the task to place the NI 9219 in voltage mode. This prevents the module from
interfering with the resistance measurements of the DMM.
c.
Configure the DMM for a 4-wire resistance measurement in the appropriate range
according to the appropriate test point from Table 19.
d.
Enable Auto Zero on the DMM.
e.
Acquire a resistance reading with the DMM. Record this measurement as
Ω
ref
.
f.
Clear the task.
3.
Disconnect the DMM from the resistor to ensure that the terminals on the DMM do not
interfere with the resistor while the NI 9219 makes measurements.
4.
Acquire and average samples.
a.
Create an AI resistance task on the NI 9219 according to Table 17.
b.
Configure the AI resistance task timing according to Table 15.
c.
Start the task.
d.
Acquire 20 4-wire resistance readings with the NI 9219.
e.
Record the average of the readings as
Ω
channel
.
Table 17.
NI 9219 Configuration for 4-Wire Resistance Accuracy Verification
Measurement
Type
Min (
Ω
)
Max (
Ω
)
Excitation
Source
Excitation
Value
Resistance
Config
4-Wire Resistance 1
k
Ω
0
1000
Internal
0.0005
4-Wire
4-Wire Resistance
10 k
Ω
10000
Table 18.
NI 9219 Timing Configuration
ADC Timing Mode
Sample Timing Type
High Resolution
On Demand
R
TestPoint
Ω
HI
LO
NI 9219
DMM
Ω
S
EN
S
E
HI
LO
EX+ (3)
HI (4)
EX– (5)
LO (6)
Ch
x