Keysight U1251B Guia Del Usuario página 87

Decibel Display
The dBm operation calculates the power delivered to a reference resistance
relative to 1mW and can be applied to DC V, AC V and AC + DC V measurements
for decibel conversion. The voltage measurement is converted to dBm by using
the following formula:
The reference resistance may be selected from 1~9999  in Setup mode. The
default value is 50 .
The decibel of voltage is calculated with respect to 1 V. The equation for the
voltage measurement is as follows:
dBV = 20 log
1 At the
NOTE
If the rotary switch is at the "~ V" position, press
dBV and the dBm measurements. The dBm or the dBV measurements can be
selected at the ACV position. The selection will be the reference for other
voltage measurements.
2 Press
Keysight U1251B and U1252B User's and Service Guide
Vin
10
,
scroll to the dBm measurement on the primary display. The secondary display
indicates the AC voltage measurement.
for more than 1 second to exit this mode.
or rotary switch position, press
Functions and Features
to switch between the
3
to
85