SIG
L
ENT
68 SDM3055 Digital Multimeter
dBm
The dBm function is logarithmic and based on a calculation of power delivered
to a reference resistance, relative to 1 mill watt. Besides
，
this function only
applies to AC voltage and DC voltage measurements.
Press
→【
dB/dBm
】→【
On
】
and select
【
Function dBm
】
to enter the
interface shown in the following diagram.
Diagram 2- 60 dBm Function Interface
Table 2- 24 dB Measurement Function Menu Function Description
Function
Menu
Settings Description
dB/dBm
On/Off
Turn on or turn off dB or dBm function.
Function
dBm
Open dBm function and the lower right corner of the
main display show “dBm”.
Ref R
Set the parameter via direction keys: 50Ω ~ 8000Ω.
Done
Save all changes and return to the higher level menu.
The computation method of the dBm:
When dBm function is turned on, the measured value of voltage is transformed
into dBm according to the following formula.
dBm = 10 x Log
10
[(Reading
2
/ R
REF
) / 0.001W]
