Appendix B: Verification
Series 2280 Precision DC Power Supply Reference Manual
B-32
077085503 / March 2019
To check DC current readback accuracy (10 A and 1 A ranges):
1. Set the voltmeter as follows:
a. Set to measure DC voltage.
b. Set the current range to autorange.
c.
Calculate the amperes (instead of volts) by multiplying the voltmeter reading result by 1/(R1), where R1
represents the high-
accuracy 0.05 Ω shunt.
2. Check the current readback accuracy on the 10 A range.
3. Set the device under test (DUT) to 100% of the full-scale output voltage.
4. Set the DUT to 0% of the test current. See the following table.
Model
Range
0% test
current (A)
10% test current
(A)
50% test
current (A)
100% test
current (A)
2280S-32-6
10 A
0
0.32
1.6
6
1 A
0
0.1
0.5
1
2280S-60-3
10 A
0
0.6
3
3.2
1 A
0
0.1
0.5
1
5. Turn the DUT output on.
6. Enter the voltmeter reading/(R1 + R2) in the
(on page B-10) table.
7. Enter the DUT current readout in the
(on page B-10) table under
the current readout column.
8. Calculate the difference of the two measurements taken in steps 7 and 8. Enter the absolute
value of the calculated value in the difference column of the
page B-10) table.
9. Increase the DUT output current to 10% of full-scale output current and repeat step 6 through
step 9.
10. Increase the DUT output current to 50% of full-scale output current and repeat step 6 through
step 9.
11. Increase the DUT output current to 100% of full-scale output current and repeat step 6 through
step 9.
12. Repeat steps 3 through 12 to check current readback accuracy on 1 A range.
