Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System - Manual (Page 13)

CDM-VW300 Series Dynamic Vibrating-Wire Analyzers
4. Overview
Single-coil vibrating-wire sensors are preferred in many applications because
they are stabile, accurate, and durable. CDM-VW300 Series Dynamic
Vibrating-Wire Analyzers make accurate high-speed measurements of the
resonant frequencies of these sensors at sub-second intervals using advanced
excitation and signal processing techniques, including spectral analysis.
Resonant frequency data are passed with diagnostics to a Campbell Scientific
datalogger. Applications include characterization of events that require rapid
measurements and data storage, and measurement of sensor signals too weak to
be measured with other instrumentation. See Appendix A, Measurement
Theory, for more information.
Dynamic vibrating-wire measurements require a complete system of
instrumentation. This manual focuses on the use of CDM-VW300 series
analyzers, but it also gives basic guidance on system configuration.
4.1 Channel Allocations
As illustrated in FIGURE 4-1, the CDM-VW300 simultaneously measures two
vibrating-wire sensors. FIGURE 4-2 shows that the CDM-VW305 has the
capacity to measure eight sensors. When more than eight channels are needed,
multiple devices are attached to the same datalogger through the CPI bus. See
Section 7.7.7, Maximum Number of Analyzers on a Datalogger, and Appendix
C, CDM Devices and CPI Bus, for details on connecting multiple analyzers to
a CPI bus.
FIGURE 4-1. Two-channel CDM-VW300 wiring panel
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