Db/Dbm - Picotest M3500A User Manual

Remote Interface Operation
Use the following commands to enable and configure MX+B function:
CALCulate:FUNCtion MXB
CALCulate:STATe {OFF|ON}
CALCulate:STATe?
CALCulate:MXB:MMFactor {<value>|MINimum|MAXimum}
CALCulate:MXB:MMFactor? [MINimum|MAXimum]
CALCulate:MXB:MBFactor {<value>|MINimum|MAXimum}
CALCulate:MXB:MBFactor? [MINimum|MAXimum]

4.3.7 dB/dBm

A. dB
Definition
The dB feature takes a DC or AC voltage measurement and displays it in
decibel unit in correspondence to a relative reference value. The
calculation of dB is listed below:
V
= ×
dB 20 log( in )
Vref
or
dB = (Input signal in dBm) – (relative value in dBm)
NOTE: The is the input signal and the is the relative reference.
※ V V
in ref
The dB measurement is applied to DC and AC voltage only. The relative
value is adjustable and is stored in a volatile memory. The range for the
relative value is between 0 dBm and 200 dBm.
How to set the relative value
You can either manually select a number for the relative reference or let
the multimeter take the first reading (0 dB).
Front Panel Operation
Press CONFIG+ SHIFT+ NULL buttons, and then use and to move
◁ ▷
through the digits and and buttons to increase or decrease the
△ ▽
numbers to your desired value. Press ENTER to set the value. The
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