Field Master Pro™ MS2090A User Guide : Real-Time Spectrum Analyzer Measurements (Option 199) : Setting Up Advanced Measurements
 
Setting Up Advanced Measurements
Refer to Making RTSA Measurements for basic information on setting up a spectrum measurement. This section provides setup information for making real time spectrum measurements. The Field Master Pro analyzer features smart measurements that make setup easy. The following sections present brief examples demonstrating the use of these measurements.
From the MEASURE menu, select one of the desired measurements.
MEASURE Menu (Spectrum)
 
MEASURE Menu
 
MEASUREMENT
Selects the desired measurement type from the following list:
• RTSA: Displays the frequency domain spectrum measurement.
• AM/FM Audio: Available when Option 24 is installed. The AM/FM Audio provides audio demodulation capability. Refer to AM/FM Audio Demodulation (Option 24).
VIEW
Selects the desired measurement view from the following list:
• Normal Spectrum View
• Spectrogram Selects Spectrogram view. When selected, a Spectrogram view is added to the display. Refer to Spectrogram View.
IQ CAPTURE
Opens the IQ CAPTURE Menu.
Refer to IQ Capture/Streaming (Option 124/126 and 125/127) for discussion of IQ Capture and Streaming.
SETUP Menu
 
SETUP Menu (Spectrogram View)
 
AM/FM SETUP
Available when Option 24 is installed. Opens the SETUP Menu (AM/FM Audio).
SHOW DENSITY
Toggles the density display on or off. Density displays the relative time density of a signal in a color scale ranging from blue to red. Signals that persist longer or more often during the acquisition time are indicated in red color. Brief transient signals are shown in blue color.
AUTOSCALE
When toggled on, automatically adjusts the DENSITY SCALE TOP and DENSITY SCALE BOT settings of the density display based on the amplitude of the signal.
DENSITY SCALE TOP
Sets the percentage of signal time for the top (red) density scale.
DENSITY SCALE BOT
Sets the percentage of signal time for the bottom (blue) density scale. Any signal that appears at a rate lower than the DENSITY SCALE BOT setting will not appear in the density plot.
DENSITY RES
Density resolution sets the FFT size of the RTSA capture. Normal resolution sets a 512 point FFT; High resolution sets a 1024 point FFT. Higher resolution gives finer frequency detail to the density display, but increases POI. Lower resolution will result in a lower POI, but gives less frequency detail to the density display.
PERSISTENCE STATE
Toggles the persistence state between Variable or Infinite. Infinite persistence means the density plot will not fade away after a signal is no longer present. It is useful for seeing very fast and infrequent signals. Variable persistence sets a user defined time for the density colors to fade. Longer persistence values can be used to best illustrate the signals being observed.
PERSISTENCE
Sets the decay time of the density display.
ACQUISITION TIME
The acquisition time sets the update interval for each spectrum trace, spectrogram line, and density display. During the acquisition interval, spectral data from multiple FFTs of the input signal are taken and combined. The acquisition time is adjustable to allow resolving multiple, brief signal events in time and to observe longer term behaviors.
COLOR SCALE TOP
Defines the amplitudes where the top color on the color setup bar are applied. Any measurement above this amplitude will appear black on the spectrogram window (shown only in Spectrogram).
COLOR SCALE BOT
Defines the amplitudes where the bottom setting colors on the color setup bar are applied. Any measurement below this amplitude will appear black on the spectrogram window (shown only in Spectrogram).
REFERENCE HUE
Allows you to customize the Spectrogram color range (Color Bar) and Hue values. The color limits and the reference hue are based on a 360-degree color wheel where default 0 is red (255 0 0) (shown only in Spectrogram).
PRESET SETUP
Presets the color setup settings.