The Metrology of VNA Measurements, Errors, and Uncertainties
A fully metrological measurement made by a VNA is comprised of a value, a unit, an uncertainty, and the confidence interval of the uncertainty. Measurement uncertainty, or accuracy, is stated on the VNA datasheet. Still, a complete understanding of the error components which contribute to overall uncertainty is helpful to inform and enable the user of the equipment to make the best possible measurements.
Resource from Doug Rytting, “Network Analyzer Error Models and Calibration Methods”
Resource from Euramet, “Calibration Guide”