Agilent Technologies 86140B Series, User Manual

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3-7
Function Reference
Amplitude Setup
Setup Panel
Selections Reference Level Position
The value selected for the Reference Level Position determines the position of
the reference level on the graticule. Setting this value to zero divisions places
the reference level on the very bottom of the grid. Setting the reference level
to 10 divisions places the reference level at the top of the grid. Pressing the
front-panel
Preset
key resets the reference level to 9.0 divisions.
N o t e When using the knob or step keys, the value will automatically change. When
using the numeric entry pad, enter a terminator that is selected from the
softkey panel.
Amplitude Units
Selecting Auto for amplitude units allows power to be shown in dBm when
using the logarithmic scale, and in watts when using the linear scale. Selecting
W forces the immediately displayed information to be in watts, regardless of
the amplitude scaling.
Auto Ranging
The Auto Range function allows the OSA to automatically change the gain of
the transimpedance amplifier during a sweep. This allows measurements to be
made at the largest dynamic range and at the fastest sweep speed.
Pressing the front-panel
Preset
key turns Auto Ranging
ON
.
N o t e It is recommended that Auto Ranging always be turned on.
Auto Zero
Turns Auto Zero
ON
and
OFF
. Auto Zero
ON
enables the internal amplifiers to
be zeroed between sweeps. Selecting
OFF
disables this feature. Pressing the
front-panel
Preset
key resets this function to
ON
.