Stanford Research Systems SR780, Operating Manual And Programming Reference

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Display Options Menu 4-35
SR780 Network Signal Analyzer
The two displays have their own number of Grid Divisions. This entry field can be linked
to both displays using the [Link] key.
Command: GDIV (?) d {, i}
PSD Units
Select PSD Units for the active display [On, Off].
Power Spectral Density (PSD) is the energy in each frequency bin normalized to the
noise bandwidth of the bin. The noise bandwidth is calculated from the FFT Linewidth
and the Window function. This compensates measurements with different Spans and
Windows. The units of the display are V
2
/Hz or V/
√
Hz.
PSD is only available for frequency domain FFT measurements. Choosing a time
domain, Octave Analysis or Swept Sine measurement turns PSD Units off and disables
this softkey.
PSD units are used in noise measurements. Most white noise sources are specified by
their noise spectral density.
The two displays have their own PSD Units mode. This entry field can be linked to both
displays using the [Link] key.
Command: PSDU (?) d {, i}
Transducer Convert
Select the Transducer Conversion for the active display [Acceleration, Velocity,
Displacement]. Transducer Convert only has an effect for measurements of inputs with
Transducer Units of acceleration, velocity or displacement. Transducer Convert is not
available for Octave Analysis measurements.
Transducers (such as accelerometers) convert a physical quantity (such as acceleration)
into a voltage at the analyzer’s input. By assigning Transducer Units to an input,
measurements based upon the transducer signal may be displayed in units of the actual
physical quantity being measured (such as m/s
2
or in/s
2
).
Transducer Convert allows measurements of inputs which are assigned input units of
acceleration, velocity or displacement to be displayed with ANY of these three units. The
conversion is accomplished in the frequency domain by multiplying by j
ω to differentiate
with respect to time and dividing by j ω to integrate over time.
The two displays have their own Transducer Conversion. This entry field can be linked to
both displays using the [Link] key.
Command: TDRC (?) d {, i}