NI 9219 Calibration Procedure
20
ni.com
2.
Create an AI bridge V/V channel on the NI 9219. Configure the channel according to Table 20.
3.
Commit the task.
4.
Configure DMM1 for a voltage measurement in the 10 V range.
5.
Enable Auto Zero on DMM1.
6.
Use DMM1 to measure the excitation voltage from the NI 9219. Record this measurement as
V
ExcitationModule
.
Note
The excitation voltage on the NI 9219 may be off if the module is not configured correctly.
The excitation value on the NI 9219 should be at least 2.5 V.
7.
Set the voltage source to V
ExcitationModule
. Use the smallest available range needed to source
V
ExcitationModule
. Using a range larger than necessary creates unwanted additional noise.
8.
Connect the NI 9219 to DMM1, DMM2, and the voltage source as shown in Figures 12, 13, or 14
for the appropriate test point value indicated in Table 21. Observe the following conditions when
connecting the equipment to the NI 9219.
•
Connect the leads of DMM1 as close as possible to the terminals on the NI 9219.
•
Connect the HI lead of DMM2 as close as possible to the same point that the HI lead of the
NI 9219 connects to the resistor network.
•
Connect the LO lead of DMM2 as close as possible to the EX– terminal of the NI 9219.
Figure 12.
Half-Bridge Accuracy Verification Connections to the NI 9219 (Configuration 2)
Table 20.
NI 9219 Configuration for Half-Bridge Accuracy Verification
Measurement
Type
Min
(V)
Max
(V)
Excitation
Source
Excitation
Value
Bridge
Config
ADC Timing
Mode
Sample
Timing Type
Half-Bridge
500 mV/V
–0.5
0.5
Internal
2.5
Half-Bridge
High
Resolution
On Demand
HI
V
LO
DMM2
NI 9219
HI
V
LO
DMM1
V+
V–
Source
EX+ (3)
HI (4)
EX– (5)
Ch
x
1 k
Ω
± 1%
1 k
Ω
± 1%
5 k
Ω
± 1%
5 k
Ω
± 1%
