Agilent Technologies 8614 B Series, User Manual, Page: 86 / 272

3-12
Function Reference
Auto Ranging (Amplitude Setup Panel)
Auto Ranging (Amplitude Setup Panel)
When on, the auto ranging allows the OSA to achieve the desired sensitivity by taking several
sweeps and switching between gain stages. The final trace data is a blended composite of each
trace taken in the different gain stages.
N o t e The sweep time (ST) that is displayed in the lower portion of the display is the time that it takes
for the OSA to sweep over one gain stage. The OSA may take up to three sweeps in three different
gain stages to make the measurement. This depends on the settings for sensitivity, reference level,
auto range and also the particular device being measured. The final data trace is a blended
composite of each trace taken in the different gain stages. For more information,
refer to “Sweep
Time” on page 3-81 .
Setting Auto Range to off will force the OSA to use a single gain stage and achieve the desired
sensitivity by applying a digital filter.
Key Path Amplitude > Amplitude Setup > Auto Range
Remote Commands SENSe:POWer:DC:RANGe:AUTO
Auto Zero (Amplitude Setup Panel)
Turns Auto Zero on and off. Auto Zero on enables the internal amplifiers to be zeroed between
sweeps. In this mode, the instrument compensates for temperature-related current drift between
each sweep. Although this “zeroing” increases amplitude accuracy, it also increases the time
between sweeps. If amplitude accuracy is not critical to your measurement, turning off auto zero
will improve throughput. Pressing the front-panel Preset key resets this function to on.
Tip: The instrument performs a more complete zeroing when the instrument is first turned on. You
can run this more complete routine anytime by pressing the Zero Now (System > More System
Functions > Service Menu > Adv Service Functions > Zero Now) softkey.
Key Path Amplitude > Amplitude Setup > Auto Zero
Related Functions Zero Now
Remote Commands CALibration:ZERO