8-2 Keysight N5221A/22A Service GuideGeneral Purpose Maintenance ProceduresError Terms8-Error TermsUsing Error Terms as a Diagnostic ToolBy examining error terms, you can monitor system performance for preventivemaintenance 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 analyzerCalibration kit devices, cables, and adapters and accessories are the mostcommon 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. Forinformation on connection technique and on cleaning and gagingconnectors, refer to “Review the Principles of Connector Care” on page 3-5or to the calibration kit’s user’s and service guide.Preventive MaintenanceIf you print or plot the error terms at set intervals (weekly, monthly and soforth), you can compare current error terms to these records. A stable systemshould generate repeatable error terms over long intervals, (for example, sixmonths). Look for the following:— A long-term trend often reflects drift, connector and cable wear, or gradualdegradation, indicating the need for further investigation and preventivemaintenance. Yet, the system may still conform to specifications. The cure isoften as simple as cleaning and gaging connectors and cables.— A sudden shift in error terms may indicate the need for troubleshooting.TroubleshootingYou can use the error terms as a tool to isolate faulty assemblies in the signalseparation group of your analyzer. You can compare the current values topreventive maintenance records or to the typical values listed in Table 8-1 onpage 8-8.
