5-28                Keysight N9912A Service Guide 
Theory of Operation
User Calibration in CAT and NA Modes
5-
The preset calibration should be re-characterized every 12 months to maintain 
accuracy. This is accomplished via the Error Terms test/adjustment in the TME. 
Refer to Chapter 3.
Under ideal conditions, a preset calibration and an OSL (open, short, load) 
calibration should give very similar results for measurements at the RF OUT 
port. 
Two Port Calibration
Two port calibration applies only when S21 or Insertion Loss measurements are 
active.
There is no “built-in” or “preset” two port calibration in the analyzer. A 
normalize calibration must be performed before making two port 
measurements.
QuickCal
The QuickCal function mathematically “extends” the preset calibration to the 
end of a cable or adapter. It is a firmware only function; it does not involve 
analyzer hardware.