Agilent Technologies N6751A User Manual page 136

Appendix B Verification and Calibration
136
CC Load Effect
Test category = performance
This test measures the change in output current resulting from a
change in output voltage from full scale to short circuit.
1
Turn off the power system and connect the current shunt, DVM,
and electronic load as shown in Test Setup figure (B). Connect
the DVM directly across the current shunt.
2
To ensure that the values read during this test are not the
instantaneous measurement of the AC peaks of the output
current ripple, several DC measurements should be made and
averaged. If you are using an Agilent 3458A DVM, you can set up
the voltmeter to do this automatically. From the instrument's
front panel, program 100 power line cycles per measurement.
Press NPLC 100 ENTER.
3
Turn on the power system and program the instrument settings
as described in the test record form under "CC Load Effect".
4
Set the electronic load for CV mode and program it to the output
channel's voltage as described in the test record form under "CC
Load Effect". The CC annunciator on the front panel must be on.
If it isn't, adjust the load so that the output voltage drops slightly.
5
Divide the voltage drop (DVM reading) across the current
monitoring resistor by its resistance to convert to amps and
record this value (Iout).
6
Short the electronic load. Divide the voltage drop (DVM reading)
across the current monitoring resistor by its resistance to convert
to amps and record this value (Iout). The difference in the
current readings in steps 4 and 5 is the load effect, which should
not exceed the value listed in the test record form for the
appropriate model under "CC Load Effect".
CC Source Effect
Test category = performance
This test measures the change in output current that results from a
change in AC line voltage from the minimum to maximum value
within the line voltage specifications.
1
Turn off the power system and connect the ac power line through
a variable voltage transformer or AC source.
2
Connect the current shunt, DVM, and electronic load as shown in
Test Setup figure (B). Connect the DVM directly across the
current shunt. Set the variable voltage transformer or AC source
to nominal line voltage.
3
To ensure that the values read during this test are not the
instantaneous measurement of the AC peaks of the output
current ripple, several DC measurements should be made and
averaged. If you are using an Agilent 3458A DVM, you can set up
the voltmeter to do this automatically. From the instrument's
front panel, program 100 power line cycles per measurement.
Press NPLC 100 ENTER.
Series N6700 User's Guide