Power Meter Mode - Keysight N9912A Service Manual

Theory of Operation
Operation in Modes

Power Meter Mode

All measurement circuitry is switched to the low power state during PM (power
meter) mode. This is the mode with the lowest power dissipation.
The analyzer has no power output capability in this mode. The analyzer
essentially functions as a display for a USB power sensor.
Keysight N9912A Service Guide 5-25