Agilent Technologies B1500A Training Manual page 77

Clean Probing Environment
What is Required?
Low loss triaxial connection (no matrix card)
Guard to tip of probe (no bare needle or probe cards)
No air flowing near probe tip (including dry nitrogen)
No hot chuck
Chuck isolated from ground (10^13 ohms)
Chuck guarded for substrate measurements
Shielded probe station
No vibration; cables stationary
Microscope light, motors, etc. off
This check list covers most sources of noise or stray capacitance. In a "clean" probing environment
the B1500A can be used with short integration time and no delay time between steps.
6-5
Module 6
Low Current Measurement