User manual

FFT Analyzer
AM700 Audio Measurement Set User Manual
4-89
Averaging
Averaging is available for the FFT Analyzer displays. Pressing the Average button
lights the label on the front panel and enables the selected type of averaging (noise
reduction) on the displayed signal (if Averaging is applicable). Pressing and holding
the Average button displays the Average menu. In that menu you can set the number
of averages (up to 9,999) and specify whether averaging is based on minimum,
maximum, or average signal values. When averaging is not applicable for a display,
the Average menu soft keys are not accessible. Refer to Averaging on page 2-12 for
more details on averaging operation.
Zooming (Expanding) the Display
When the touch and zoom feature of the AM700 is used to rapidly expand or shrink
the display horizontally, the trace expands and shrinks at a rate determined by the
current bin resolution. As soon as the analyzer acquires new data at the new bin
resolution, the trace data is updated to reflect the new bin width. That width is
displayed in the upper left corner of the view window. At maximum span (no zoom)
the bin width is 46.87 Hz per bin in the high resolution mode. At maximum zoom,
the bin width is 0.4687 Hz per bin. If you want to expand the display without having
the new acquisition rescaling the horizontal trace, press Freeze first. The acquired
data is held and zooming works on that data without rescaling. A maximum zoom
display is shown in Figure 4-41.