Agilent Technologies N5241A, Service Manual

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Service Guide N5242-90001 8-3
PNA Series Microwave Network Analyzers General Purpose Maintenance Procedures
N5241A/42A Error Terms
Error Terms
Using Error Terms as a Diagnostic Tool
By examining error terms, you can monitor system performance for preventive
maintenance and troubleshooting purposes.
The magnitude and shape of the error terms are affected by:
• calibration kit devices
• cables
• adapters and accessories
• the assemblies from the signal separation group of the analyzer
Calibration kit devices, cables, and adapters and accessories are the most common cause of
error term anomalies. Make sure of the following:
• Connectors must be clean, gaged, and within specification.
• Use proper connection technique during measurement and calibration. For information
on connection technique and on cleaning and gaging connectors, refer to “Review the
Principles of Connector Care” on page 3-5 or to the calibration kit’s user’s and service
guide.
Preventive Maintenance
If you print or plot the error terms at set intervals (weekly, monthly and so forth), you can
compare current error terms to these records. A stable system should generate repeatable
error terms over long intervals, (for example, six months). Look for the following:
• A long-term trend often reflects drift, connector and cable wear, or gradual degradation,
indicating the need for further investigation and preventive maintenance. Yet, the
system may still conform to specifications. The cure is often as simple as cleaning and
gaging connectors and cables.
• A sudden shift in error terms may indicate the need for troubleshooting.
Troubleshooting
You can use the error terms as a tool to isolate faulty assemblies in the signal separation
group of your analyzer. You can compare the current values to preventive maintenance
records or to the typical values listed in
Table 8-5 on page 8-10 .
To find assemblies related to error term failures, refer to error term descriptions in “Error
Term Data” on page 8-10 . Each description lists common assemblies related to each error
term. Identify the assembly and refer to Chapter 4, “Troubleshooting.”
NOTE
Always suspect calibration devices, cables, or improper connector
maintenance as the primary cause of an error term anomaly.