Keysight Technologies M937 A PXIe Series Service Manual page 17

General Product Information
Error Terms
S ) with loads attached to both ports during the measurement calibration.
12
Isolation errors affect transmission measurements primarily where the
measured signal level is very low.
The measurements most affected by isolation error terms are DUTs with large
insertion loss. Since these terms are low in magnitude, they are usually noisy
(not very repeatable).
Typical Cause of Failure
A loose cable connection or leakage between components is the most likely
cause of isolation problems.
After verifying the cable and its connections, the analyzer requires repair. Refer
to "Shipping Your Network Analyzer for Service or Repair" on page 1-3.
1-12 Keysight M937xA PXIe Service Guide