Theory of Dynamic Signal Analysis
Dynamic Signal Analysis Basics.pdf (32 pages, 1.1 MB)
Describes the basic dynamic signal analysis theory including Fourier Transform, data windowing, linear spectrum, power spectrum, cross spectrum, FRF and coherence, averaging, transient capture and hammer test, overlapping process, SDOF system.
Dynamic Signal Analysis Advanced.pdf (75 pages, 1.85 MB)
Describes the advanced dynamic signal analysis theory including swept sine test with tracking filter, real-time digital filters, octave analysis, sound level meters, order tracking analysis, automated test, shock response spectrum analysis.
VDC Signal Analysis.pdf (32 pages, 0.7 MB)
Describes algorithms used in vibration analyzers, including computing the RMS, Peak, Peak-Peak values, FFT spectrum, demodulation spectrum and digital integration for transforming acceleration into velocity or displacement
Product and Application Notes
Modal testing on hockey sticks.pdf (2 pages, 340 KB)
Modal testing on hockey sticks.
130-150dB Dynamic Range.pdf (3 pages, 219 KB)
Describes how CI defines the dynamic range of the measurement system.
Audio Functions.pdf (5 pages, 211.95 KB)
This paper presents the advanced audio functions, including microphone, earphone and voice annotation.
Applying ASAM-ODS in CoCo-80.pdf (5 pages, 288.23 KB)
ASAM-ODS is a new industrial standard of data format that are particularly designed for dynamic measurement systems. CoCo-80 is the first handheld instrument that complies with this new data format.
Wireless Remote Monitoring.pdf (5 pages, 334.92 KB)
CoCo-80 can be used as a remote monitoring device. This application note describes how it is used for construction noise monitoring.
Modal Data Acquisition.pdf (16 pages, 953.85 KB)
Explains how the CoCo-80 interfaces to the modal analysis software and how the modal data is captured.
Manage DSA Signals using Database.pdf (11 pages, 1.45 MB)
Describes how thousands of data files can be conveniently managed by the EDM database tool.
Time Synchronous Average.pdf (5 pages, 422 KB)
Describes how the time synchronous averaging is applied to the rotating machine analysis.
Configurable Signal Analysis.pdf (Paper published on Sound and Vibration Magazine, 3MB)
This feature allows the user to dynamically configure the DSP functions so that data processing flow can be customized from application to application. All the user has to do is create a "CSA script" using a graphical interface (no coding is required). This feature is included with all CoCo-80's and CoCo-90.
Anti-Aliasing Filter and Phase Match.pdf (5 pages, 636 KB)
Crystal Instruments is among the very first companies using sigma-delta converters in early 90s. This paper discussed the sigma-delta converter, anti-aliasing filter and phase match issues in a DSA instrument.
VCS History (paper published on Sound and Vibration Magazine, 0.4MB)
This article discusses the four generations of digital vibration control systems developed by US companies in the past 4 decades.
