Making Difference Measurements - Agilent Technologies E4419B User Manual

2 Power Meter Operation

Making Difference Measurements

Dual channel difference measurements can be made on the currently selected
window by pressing
The power meter always carries out "Maths" calculations in Watts. The power
meter displays the numerical difference of the power values of both channels
in dBm or Watts. The power value for each channel includes offsets,
calibration factors and duty cycle in addition to measured power. The filter,
range (where applicable), offset, duty cycle and calibration factor are set
individually for each channel.
Logarithmic units (dBm) can be used in A-B difference measurements where
the channel A power level is less than the channel B power level. Likewise,
logarithmic units can be used in B-A difference measurements where the
channel B power level is less than the channel A power level. However, the
negative sign is ignored and a log error is displayed on the status line and in
the error queue.
Difference measurements can be displayed relative to a stored reference. In
relative mode, readings are displayed in either dB or %. Refer to
Relative Measurements"
80
, Input Select ,
on page 64 for further information.
, and selecting A-B
"Making
E4419B Power Meter User's Guide
or B-A .