GW Instek GDM-8300 series User Manual - Manual (Page 63)

OPERATION
63
dBm/dB/W Measurement
dBm/dB Calculation
Overview Using the ACV or DCV measurement results,
the DMM calculates the dB or dBm value based
on a reference resistance value in the following
way:
dBm= 10 x log
10
(1000 x Vreading 2 / Rref)
dB= dBm – dBmref
W= Vreading 2 /Ref
Where:
Vreading= Input Voltage, ACV or DCV;
Rref= Reference resistance simulating an output
load;
dBmref= Reference dBm value
Measuring dBm/W
Procedure 1. Select ACV or DCV measurement. See page 33.
2. To measure dBm, press SHIFT → .
The primary display will show the dBm
measurement while the secondary display
shows the reference resistance.