Agilent Technologies Twelfth 4287A RF LCR Operation Manual page 78

Function Overview
Names and Functions of Parts on the Front Panel
NOTE To prevent the 4287A from malfunctioning, do not apply DC voltage or DC current to the
test head's DUT port. The capacitor in particular could be charged. When you connect a
capacitor, discharge it sufficiently before connecting it to the test fixture that is connected
to the test head's DUT port.
78 Chapter 4