Keysight E3631A - Measurement Techniques; Figure 3-1 Performance Verification Test Setup

3 Calibration Procedures
54 Keysight E3631A Service Guide
Measurement techniques
Setup for most tests
Most tests are performed at the front terminals as shown in the following figure.
Measure the dc voltage directly at the (+) and (-) terminals on the front panel.
Figure 3-1 Performance verification test setup