Table 3.
Voltage Output and Measurement Verification
Level
Range
Limit
Range and
Limit
Test Point
As-Found
Measurement Test
Limit (% of V
Offset)
As-Left Measurement
Test Limit (% of Voltage
+ Offset)
600 mV
1 mA
-600 mV
0.02% + 100 μV
0.0065% + 25 μV
0 mV
600 mV
6 V
1 mA
-6 V
0.02% + 600 μV
0.0045% + 85 μV
0 V
6 V
60 V
1 mA
-60 V
0.02% + 6 mV
0.0065% + 820 μV
0 V
60 V
1.
Set the first specified level range, limit range, and limit on the NI 4138.
2.
Measure the internal device temperature and perform self-calibration if necessary.
a)
If the internal device temperature exceeds T
cal
± 1 °C, wait up to 5 minutes for the
temperature to stabilize to within T
cal
± 1 °C.
b)
If after 5 minutes the stable temperature still exceeds T
cal
± 1 °C, call the self-
calibration VI or function.
3.
Set the level on the NI 4138 to the first specified test point.
4.
Compare a DMM voltage measurement to the voltage measurement test limits.
a)
Take a voltage measurement using the DMM.
b)
Calculate the lower and upper voltage measurement test limits using the following
formula: Voltage Measurement Test Limits = Test Point ± (|Test Point| * % of
V Offset ).
c)
Verify the DMM measurement falls within the test limits.
5.
Repeat the previous steps, from setting the level to the test point on the NI 4138 up to this
step, for each specified test point in the level range.
6.
If more than one level range is specified, repeat the previous steps using the values
specified in each level range.
Verifying Voltage Remote Sense
Use the NI 4138 in constant current mode with a test circuit to simulate the voltage drop
between the device and a load.
Complete this procedure only after successfully completing all previous verification
procedures. Verify ranges in the specified order.
NI PXIe-4138 Calibration Procedure
|
© National Instruments
|
7