Power Meter : General Information : Power Meter
  
Power Meter
Instruments equipped with the Power Meter measurement mode can be used to make channelized power meter measurements. No external sensor is required.
High Accuracy Power Meter
Instruments with Option 19 and an appropriate sensor can be used to make High Accuracy Power Measurements. This option provides true RMS measurements with accurate measurements for both CW and complex digitally modulated signals. Option 19 Power Sensors lists the Option 19 compatible Anritsu sensors.
Note 
Sensors are not included with Option 19. They must be purchased separately.