Features and Functions | 3 |
Decibel Display
The dBm operation calculates the power delivered to a reference resistance relative to 1 mW 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 Ω in
Setup mode. The default value is 50 Ω.
The decibel of voltage is calculated with respect to 1 V. The equation for the voltage measurement is as follows:
dBV = 20 log10 Vin
1 At the 
, 
, or 
rotary switch position,
press 
to scroll to the dBm measurement on the primary display. The secondary display indicates the AC voltage measurement.
| N O T E | If the rotary switch is at the “~ V” position, press | to switch |
| between the 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 
for more than 1 second to exit this mode.
Agilent U1251A/U1252A User’s and Service Guide | 57 |
