Keysight N9927-90001 User’s Guide                                                            301
Power Meter (USB) Mode - Option 302
USB Power Meter Settings
USB Power Meter Settings
Select Power Meter Mode before making any setting in this section.
How to select Power Meter Mode
—Press Mode_. 
—Then Power Meter (USB Sensor)
.
Average / Peak 
—Press Measure 1
— Then choose from the following:
— Average
 Measures and reports the average of the power 
measurements.
— Peak
 Available ONLY on the U202x power sensors. Measures and 
reports peak power detected at sensor input.
Zeroing
The Keysight USB Power Sensors perform Internal Zeroing automatically. 
Because Keysight USB Power Sensors have an internal switch, Internal Zeroing 
does NOT require that the power source be turned OFF. 
For highest measurement accuracy, when measuring power levels below –30 
dBm, External Zeroing should be performed. 
During External Zeroing, the power source MUST be turned OFF or the power 
sensor disconnected from the power source (device under test). Power is OFF 
when power sensor measurements are below –60 dBm. When power higher 
than this is detected at the sensor, a warning message is shown on the 
FieldFox and External Zeroing will not proceed.
How to perform External Zeroing
—Press Cal 5.
—Then External Zero
.
While either Internal or External Zeroing is being performed, “Zeroing...” is 
shown on the FieldFox screen. While this message is present, do NOT make 
any changes to the FieldFox. 
External Zeroing is NOT allowed on the U2020 X-series Power Sensors.