Campbell AVW200 series, Instruction Manual

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AVW200-series 2-Channel Vibrating
Wire Spectrum Analyzer Modules
The AVW200 series consist of a base model (AVW200) and three wireless models
(AVW206, AVW211, AVW216). The wireless models combine the AVW200 with a spread
spectrum radio. The different model numbers of the wireless versions are for different
spread spectrum frequency ranges.
Compatible Radios
•
AVW206—910 to 918 MHz (US/Canada) RF401
•
AVW211—920 to 928 MHz (Australia/Israel) RF411
•
AVW216—2.4 GHz (worldwide) RF416
Throughout this manual AVW200 will refer to all models unless specified otherwise.
Likewise, AVW206 typically refers to all wireless models, and RF401 refers to the
corresponding spread spectrum radio.
1. Overview
The AVW200 module allows the measurement of vibrating-wire strain gauges,
pressure transducers, piezometers, tiltmeters, crackmeters, and load cells.
These sensors are used in a wide variety of structural, hydrological, and
geotechnical applications because of their stability, accuracy, and durability.
Up to two vibrating wire or vibrating strip transducers can be connected to the
AVW200. More sensors can be measured by using multiplexers (see Section
1.4).
1.1 Design Features
Historically, vibrating-wire sensors suffered from one major problem—
external noise. The AVW200 significantly reduces and, in most cases,
eliminates the problem of incorrect readings due to noise sources. The noise
problems were overcome by advancement in technology and mathematical
processing
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, resulting in frequency based measurements—a complete departure
from previous time-domain based measurements.
Read more! Vibrating Wire Measurements are discussed in detail in
Section 2.
To simplify programming of the AVW200, engineers implemented firmware to
eliminate several parameters that were necessary in programming the older
Campbell Scientific interfaces (i.e., AVW1, AVW4, AVW100).
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U.S. Patent No. 7,779,690
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