Figure 8.
Current Verification or Adjustment Connection Diagram
NI-DCPower Device
Sense –
Sense +
+
–
+
–
Precision
Shunt
DMM
Voltage
Mode
2.
Set the
niDCPower Output Function
property or
NIDCPOWER_OUTPUT_FUNCTION
attribute to DC Current for the NI 4113.
Adjusting Current Output and Measurement
Compare a set of currents measured by the external DMM to both a set of current test points
requested by the NI 4113 and to the measured currents reported by the NI 4113.
Refer to the following table as you complete the following steps.
Table 10.
Current Output and Measurement Adjustment
Level Range
Limit Range and Limit
Test Point
6 A
10 V
0.1 A
6 A
1.
Set the first specified level range, limit range, and limit on the NI 4113.
2.
Set the level on the NI 4113 to the first specified test point.
3.
Calculate the current through the shunt by completing the following steps.
a)
Take a voltage measurement across the shunt using the DMM.
b)
Divide the voltage measurement by the calibrated value of the shunt.
4.
Store the value from the previous step as input for the niDCPower Cal Adjust VI or
function called in the following steps.
5.
Take a current measurement using the NI 4113.
6.
Store the value from the previous step as input for the niDCPower Cal Adjust VI or
function called in the following steps.
7.
Repeat the previous five steps for each test point specified in the level range.
8.
Update the measurement calibration constants by configuring and calling the niDCPower
Cal Adjust Current Measurement VI or
niDCPower_CalAdjustCurrentMeasurement
function.
a)
Input the DMM measurements as the
measured outputs
.
16
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NI PXIe-4113 Calibration Procedure
