CISPR 16-1-1 Compliance with Internal Instrument Alignments set to OFF

Customers have asked Keysight Technologies about the requirement to run Internal Instrument Alignments and EMI RF preselector alignments during their EMI Testing using the N9048B PXE EMI Receiver. The default mode setting of the X-Series Analyzers Internal Alignments is AUTO. This is the mode in which the printed specifications for our Analyzers are created, and so it is therefore recommended that for the full printed Analyzer specifications to be met, the Alignments must be kept in the default mode setting of AUTO. RF preselector Alignments are always run manually to minimize mid test interruptions.Keysight Investigated over a 100 hour test period using the N9048B PXE - held in a temperature stable environment, with a maximum ambient temperature variation of 1 Degree Centigrade, if the Alignments were set to OFF, could the EMI Receiver still provide CISPR compliant measurements according to CISPR 16-1-1?. Previously we had undertaken similar testing for the other Alignment modes (PARTIAL & LIGHT) when using the N9048B PXE EMI Receiver and during those tests we had noted that the Internal alignments required to be run, are triggered more by temperature changes, than time triggered alignment expiration events Keysight ran a full Instrument Alignment and RF Preselector Alignment at the start of the 100 hour test period and then turned OFF the Instrument Alignments and ran the required CISPR 16-1-1 specified EMI detector tests. These tests were done to gather an initial set of measurement results for comparison with further repeated measurements throughout the whole test period to help identify any variance and confirm compliance with the CISPR test limits at all times during the test.Keysight tested the N9048B PXE EMI Receiver using these CISPR 16-1-1 2019 specified tests: (5.2.2) QUASI-PEAK Variation with repetition frequency (6.4 Table 7) PEAK to QUASI-PEAK Ratio(7.3.2) EMI AVERAGE Variation with repetition frequency(7.3.3) EMI AVERAGE Narrowband Disturbance(8.3.3) RMS AVERAGE Variation with repetition frequency(8.3.4) RMS AVERAGE Narrowband Disturbance(5.2.1) QUASI-PEAK Amplitude relationship (absolute calibration)(6.4) PEAK Response to pulses (7.3.1) EMI AVERAGE Response to pulses (8.3.2) RMS AVERAGE Response to pulses  Keysight gathered and analyzed the data over the 100 hour test period and were able to confirm that during this time, the N9048B PXE EMI Receiver can make CISPR 16-1-1 2019 compliant measurements when the internal Instrument alignments are set to OFF. These requirements were met when using the RF1 and RF2 ports of the N9048B PXE at appropriate test frequencies and used within a maximum internal Instrument and room temperature variance of 1 degree.