Keysight N5227A - Error Terms; Using Error Terms as a Diagnostic Tool; Performing Measurement Calibration

Service Guide N5227-90001 8-3
PNA Series Microwave Network Analyzers General Purpose Maintenance Procedures
N5227A 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 the most common causes of error term anomalies are:
• calibration kit devices
•cables
• adapters and accessories
• the assemblies from the signal separation group of the analyzer
These items also affect the magnitude and shape of the error terms. For highest measurement accuracy,
make sure of the following:
• Use proper connector care. 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.
Performing Measurement Calibration
A calibration must be performed to allow the analyzer to calculate the error terms before they can be used