Measurement Traceability - Keysight P937 A Series Service Manual

Tests, Adjustments, and Troubleshooting
System Verification
— reflection and transmission frequency tracking, and
— isolation (crosstalk)
The random errors include:
— noise
— drift
— connector repeatability
— test cable stability
A complete description of system errors and how they affect measurements is
provided in the network analyzer's Help system (search for Measurement
Errors).
Any measurement result is the vector sum of the actual test device response
plus all error terms. The precise effect of each error term depends on its
magnitude and phase relationship to the actual test device response. When
the phase of an error response is not known, phase is assumed to be
worst-case (–180° to +180°). Random errors such as noise and connector
repeatability are generally combined in a root-sum-of-the-squares (RSS)
manner.

Measurement Traceability

To establish a measurement traceability path to a national standard for a
network analyzer system, the overall system performance is verified through
the measurement of devices that have a traceable path. This is accomplished
by measuring the devices in a Keysight verification kit.
The measurement of the devices in the verification kit has a traceable path
because the factory system that measured the devices is calibrated and
verified by measuring standards that have a traceable path to the National
Institute of Standards and Technology (NIST) (see Figure 3-4).
Keysight P937xA PXIe Service Guide 37