HP E4418B Programming Manual page 437

UNIT Subsystem
UNIT[1|2]:POWer <amplitude_unit>
Parameters
Example
Reset Condition
On reset, both channels are set to dBm.
13-4
Item Description/Default
amplitude_unit The measurement unit. The
default unit is dBm.
UNIT1:POW DBM
Range of Values
W
DBM
This command sets the
measurement units for the upper
window and the default units for
any relevant SENSe1 command to
dBm.
HP E4418B/E4419B Programming Guide