SRS Labs SR785 - Manual (Page 4)

SR785 Two Channel Dynamic
Signal Analyzer
FFT Spectrum Analysis
The SR785 Two Channel Dynamic Signal Analyzer is a
precision, full-featured signal analyzer that offers
state-of-the-art performance and a wide selection of features
at a price that's less than half that of competitive analyzers.
Building on its predecessor, the SR780, the SR785
incorporates new firmware and hardware that make it the
ideal instrument for analyzing both mechanical and electrical
systems. Whether your measurements involve modal analysis,
machinery diagnostics, vibration testing, servo systems,
control systems, or acoustics, the SR785 has the features and
specifications to get the job done. Standard measurement
groups include FFT, order tracking, octave, swept-sine,
correlation, time capture and time/histogram. The SR785
brings the power of several instruments to your application –
a spectrum analyzer, network analyzer, vibration analyzer,
octave analyzer and oscilloscope.
A unique measurement architecture allows the SR785 to
function as a typical dual channel analyzer with measure-
ments like cross spectrum, frequency response, coherence,
etc. Alternatively, the instrument can be configured so that
each input channel functions as a single channel analyzer with
its own span, center frequency, resolution, and averaging.
Bottom display shows a wideband FFT, while the
top display shows a narrowband FFT of the same
signal. The sideband marker has been selected for
calculation of the total sideband power.
This allows you to view a wideband spectrum and
simultaneously zoom in on spectral details.
The same advanced architecture provides storage of all
measurement building blocks and averaging modes. Vector
averaged, RMS averaged, unaveraged and peak hold versions
of all measurements are simultaneously acquired and can be
displayed without re-taking data.
Averaging
The SR785 comes equipped with a wide selection of
averaging techniques to improve your signal to noise ratio.
Choose RMS averaging to reduce signal fluctuations, vector
averaging to actually eliminate noise from synchronous
signals, or peak hold averaging. In the order-tracking
measurement group, time averaging is available. Both linear
and exponential averaging are provided for each mode.
The SR785 is so fast, there's no need for a separate "fast
averaging" mode. Averaging is always fast, and the display
update rate is never sacrificed to increase the averaging rate.
For instance, in a full span FFT measurement with a 4 ms
Use the SR785 to monitor the fundamental and
harmonics of your signal. Total harmonic power
and THD are calculated in real-time for fast,
accurate analysis.