Keysight E3631A, Service Manual

Page: 61 / 131

Calibration Procedures 3
Keysight E3631A Service Guide 59
9 Readback the output voltage of the selected output over the remote interface
by sending the command:
MEAS:VOLT? {P6V|P25V|N25V}
10 Record the value displayed on the controller. This value should be within the
limits specified below for the output to be tested.
11 Repeat steps (1) through (10) for the remaining outputs.
CV load regulation
This test measures the immediate change in the output voltage resulting from a
change in the output current from full to no load.
1 Turn off the power supply and connect a digital voltmeter between the (+) and
(-) terminals of the output to be tested as shown in Figure 3-1 .
2 Turn on the power supply and select the desired output to be tested using the
meter and adjust selection key on the front panel. Enable the outputs and set
the display to the limit mode. When the display is in the limit mode, program
the current of the selected output to the maximum programmable value and
the voltage to the full rated value (see Table 3-2 ).
3 Operate the electronic load in constant current mode and set its current to the
full rated value of the output to be tested (see Table 3-2 ). Check that the front
panel CV annunciator remains lit. If not lit, adjust the load so that the output
current drops slightly until the CV annunciator lights. Record the output
voltage reading on the digital voltmeter.
4 Operate the electronic load in open mode (input off). Record the output
voltage reading on the digital voltmeter immediately. The difference between
the digital voltmeter readings in steps (3) and (4) is the CV load regulation. The
difference of the readings during the immediate change should be within the
limit specified below for each output tested.
Output Readback Accuracy
+6V Output DVM ± 11 mV
+25V Output DVM ± 22.5 mV
-25V Output -(DVM ± 22.5 mV)