NI 9219 Calibration Procedure
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© National Instruments Corporation
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11
c.
Commit the task.
d.
Acquire a current reading with the DMM.
e.
Record this measurement as I
ref
.
f.
Acquire 20 current readings per channel on the NI 9219.
Note
Perform the DMM measurements and the NI 9219 measurements as
simultaneously as possible in order to reduce error from drift in the current source.
g.
Record the average of the readings for each channel as I
channel
X
.
h.
Clear the task.
6.
Perform the following calculation using the recorded I
ref
and I
channel
X
values for each
channel.
7.
Compare the calculation result for each channel to the Upper Limit and Lower Limit values
in Table 10.
Note
The test limits listed in Table 10 are derived using the values in Table 53.
8.
Set the source to zero.
9.
Repeat steps 2 through 8 for all test points listed in Table 10.
10. Repeat steps 2 through 9 for all channels listed on the NI 9219.
11. Disconnect the source and the DMM from the device.
2-Wire Resistance Accuracy Verification
Complete the following steps to verify the 2-wire resistance accuracy of an NI 9219.
Table 9.
NI 9219 Timing Configuration
ADC Timing Mode
Sample Timing Type
High Resolution
On Demand
Table 10.
NI 9219 Verification Test Limits for Current Accuracy
Range
Test Point
1
–
Year Limits
Minimum
(mA)
Maximum
(mA)
Location
Value (mA)
Lower Limit
(mA)
Upper Limit
(mA)
–25
25
Max
19.0
–0.02089
0.02089
Mid
0.0
–0.00061
0.00061
Min
–19.0
–0.02089
0.02089
Accuracy
I
channelX
I
ref
–
=