Making Difference Measurements - Agilent Technologies E4419B User Manual

Power Meter Operation

Making Difference Measurements

Making Difference Measurements
Dual channel difference measurements can be made on the currently
Meas
selected window by pressing , , and selecting
Input Select
More
Setup
or . The power meter always carries out "Maths" calculations in
A-B B-A
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
"Making Relative Measurements", on page 2-37 for further information.
Agilent E4419B User's Guide 2-53