Measurement Uncertainty; Measurement Traceability - Agilent Technologies HP 8719D Service Manual

factory measured verification data, uncertainty limits of an HP 871OD/20D/22D
system, and a printout of the factory uncertainties for the devices in the kit.
Measurement
Uncertainty
Measurement uncertainty is defined as the sum of the residual systematic
(repeatable) and random (non-repeatable) errors in the measurement system
after accuracy enhancement. The systematic errors are directivity, source
match, load match, reflection and tr ansm&sion frequency tracking, and
isolation (crosstalk). Random errors include errors due to noise, drift, connector
repeatability, and test cable stability. A complete description of system errors
and how they affect measurements is provided under the "What is Measurement
Calibration?" section of Chapter 6 in the HP 8719o/2oo/x2
Any measurement result is the vector sum of the actual test device response
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. F'or more
information on determining measurement uncertainties, refer to Appendix A,
"Determining System Measurement Uncertainties W

Measurement Traceability

network analyzer system, the overall system performance is verified through
the measurement of device characteristics that have a traceability path. This is
accomplished by electrically measuring devices in an HP veritlcation kit.
The measurement of the verification kit device characteristics has a traceable
path because the factory system that characterizes the devices is calibrated
and verified by measuring standards that have a traceable path to the National
Institute of Standards and 'Rxhnology (NISI'), see Figure 2-7. This chain of
measurements defines how the verification process brings traceability to the HP
is veriiled through the performance of the "System Veri&ation" procedure, a
measurement traceability path is established.