Keysight Truevolt Series Operating And Service Manual page 105

Features and Functions
dBm Scaling
The dBm function is logarithmic, comparing power delivered to a reference resistance, relative to 1 mil-
liwatt:
dBm = 10 x log ( reading
10
The reference resistance value ( Ref R ) may be 50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500, 600
(default), 800, 900, 1000, 1200, or 8000 Ω. Press Ref R and use the front panel up and down arrows to
make your selection.
dBm scaling applies to ACV and DCV measurements only.
% Scaling
% performs a percent change operation. The result is the percent change of the measurement from the ref-
erence value:
Result = ((Measurement – Reference) / Reference) * 100.
Press Measure Reference to use the first measurement as the reference value, or press Ref Value to spe-
cify the reference value.
% scaling applies to all measurement functions except Ratio, Continuity, and Diode.
Mx-B Scaling
For Mx-B scaling, the result is the measurement multiplied by the Gain (M) value minus the Offset (B)
value.
The User Units softkey allows you to specify the custom alphanumeric label of up to four characters (for
example, RPM or °C) for Mx-B scaled measurements.
Mx-B scaling applies to all measurement functions except Ratio, Continuity, and Diode.
106
2
/ reference resistance / 1 mW )
Keysight True volt Series Operating and Service Guide