AVW200 2-Channel Vibrating Wire Analyzer Module
Greatly Reduces Signal Noise
Using patented VSPECT® technology for better readings
weather applications supported water applications supported energy applications supported gas flux & turbulence applications supported infrastructure applications supported soil applications supported

Overview

With an AVW200 vibrating wire analyzer module, your data logger can measure vibrating wire strain gages, 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.

Learn about our patented VSPECT® spectral-analysis technology at our VSPECT Essentials web resource.

The dynamic vibrating wire measurement technique is protected under U.S. Patent No. 8,671,758, and the vibrating wire spectral-analysis technology (VSPECT®) is protected under U.S. Patent No. 7,779,690.

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Benefits and Features

  • Provides better measurements by significantly reducing incorrect readings caused by noise sources
  • Interfaces two vibrating wire sensors; more sensors may be connected if an AM16/32B multiplexer is used
  • Self-checking diagnostics give continual feedback on sensor condition
  • High resolution—less than 0.001 Hz (industry standard is 0.1 Hz)
  • Low current drain
  • Interfaces both temperature and frequency measurements from vibrating wire sensors

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Technical Description

The AVW200 uses vibrating wire spectral-analysis technology (VSPECT). VSPECT observes the incoming sensor signal, performs a Fourier transform and a spectral analysis (transforming the time series into individual sinusoidal components in the frequency spectrum), and determines the sensor frequency by identifying the largest signal in the acceptable range while filtering out environmental and electrical noise.

The AVW200 analyzer module also provides many self-checking diagnostics such as vibrating element signal strength, signal-to-noise ratio, vibrating element signal decay ratio, and incorrect signal response. These diagnostics can be running in the background to give continual feedback of the condition for each sensor.

Specifications

-NOTE- Electrical specifications are valid over a -25° to +50°C range unless otherwise specified. Non-condensing environment required.
Number of Vibrating Wire Sensors Measured Up to 2 vibrating wire sensors can be connected to the analyzer module. Additional sensors can be measured by using an AM16/32-series multiplexer.
Power Requirements 9.6 to 16 Vdc
Analog Input/Outputs 2 differential (DF) vibrating wire measurements (V+ and V-) and 2 single-ended (SE) ratiometric resistive half-bridge measurements (T+ and T-) for vibrating wire sensor's onboard temperature sensor.
Digital Control Ports 3 digital control ports (C1 – C3)
  • C1 functions as an SDI-12 I/O communication port.
  • C2 functions as a Clk output for multiplexer control.
  • C3 functions as a Reset output for multiplexer control.
RS-232 Port 1 9-pin RS-232 port (for connecting to a data logger COM port)
Measurement Resolution 0.001 Hz RMS (±250 mV differential input range; -55° to +85°C)
Measurement Accuracy ±0.013% of reading (±250 mV differential input range; -55° to +85°C)
Input Voltage Range ±250 mV (differential) for vibrating wire inputs
Common Mode Range ±25 V
Baud Rates Selectable from 1200 to 38.4 kbps. (ASCII protocol is one start bit, one stop bit, eight data bits, and no parity.)
Memory
  • Either 128 or 512 kB of SRAM
  • 2 MB of OS Flash
CE Compliance Standards to which Conformity Is Declared IEC61326:2002
Dimensions 21.6 x 11.18 x 3.18 cm (8.5 x 4.4 x 1.25 in.)
Weight 0.43 kg (0.95 lb)

Typical Current Drain @ 12 Vdc

Quiescent, Radio Off ~0.3 mA
Radio Duty Cycling 1 s ~3 mA (includes quiescent current)
Radio Always On ~26 mA (radio transmit current 100 mA)
Active RS-232 Communication ~6 mA (3 s after communication stops, the current will drop to the quiescent current.)
Measurement ~25 mA (averaged over the 2 s)

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Dataloggers

Product Compatible Note
21X (retired)
CR10 (retired) The CR10 supports the SDI-12 mode only.
CR1000 (retired)
CR1000X
CR10X (retired) The CR10X supports the SDI-12 mode only.
CR200X (retired)
CR211X (retired)
CR216X (retired)
CR23X (retired) The CR23X supports the SDI-12 mode only.
CR300
CR3000 (retired)
CR310
CR350
CR500 (retired)
CR5000 (retired) The CR5000 supports the SDI-12 mode only.
CR510 (retired)
CR6 The CR6 is compatible with the AVW200. However, because the CR6 has built-in vibrating wire measurement capabilities, the AVW200 is unnecessary.
CR800 (retired)
CR800 (retired)
CR800 (retired)
CR800 (retired)
CR850 (retired)
CR850 (retired)
CR9000 (retired)
CR9000X (retired)

Mounting Equipment

Product Compatible Note
ENC10/12 If using the RS-232 port, the AVW200 must be mounted flat to fit in an ENC10/12.
ENC12/14 If using the RS-232 port, the AVW200 must be mounted flat to fit in an ENC12/14.
ENC14/16

Miscellaneous

Product Compatible Note
ENC10/12R If using the RS-232 port, the AVW200 must be mounted flat to fit in an ENC10/12R.
ENC16/18

Additional Compatibility Information

Sensors

The AVW200 Vibrating Wire Spectrum Analyzer Module allows our data loggers to measure vibrating wire strain gauges, pressure transducers, piezometers, tiltmeters, crackmeters, and load cells.

Data Logger Connections

When using SDI-12, a three-conductor cable is required; Campbell Scientific recommends the CABLE3CBL-L cable. When using RS-232, the module attaches to the data logger’s RS-232 port via the 18663 null modem cable, or attaches to control ports on a CR800, CR850, CR1000, or CR3000 datalogger via the 17855 data cable.

Enclosure Considerations

The AVW200 requires a desiccated, non-condensing environment. A Campbell Scientific enclosure is recommended when the analyzer module is in the field. The AVW200 has built-in keyhole flanges for mounting to an enclosure backplate.

Power Considerations

The AVW200 is typically powered by the data logger's power supply.

Downloads

AVW200 OS v.06 (551 KB) 10-06-2016

Current AVW200 firmware. Use the Device Configuration Utility version 1.13 or greater to send firmware and to configure the AVW200.

View Revision History

Related FAQs

Number of FAQs related to AVW200: 9

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  1. Two multiplexers, each with a maximum of 16 or 32 sensors per multiplexer, can be attached. If temperature measurements are excluded from each sensor, 32 sensors are possible.

  2. Dozens of AVW200-series modules can be accessed through one CR1000. The limiting factor is the frequency at which the CR1000 is set to retrieve data from each module. If the CR1000 needs to collect data very frequently from the modules, fewer AVW200-series modules can be accommodated in the time between data collection events.

  3. The AVW200-series modules are not required, but they do reduce the chance of erroneous readings by filtering electrical noise that is sometimes present.

  4. Two probable causes are the following:

    • The SerialOpen() instruction has not been added to the datalogger code.
    • The correct PakBus address setting has not been used in the AVW200 instruction.
  5. It takes 2 s for the AVW200-series modules to acquire a measurement from each sensor. An AVW200-series module servicing two AM16/32B multiplexers, each with 16 vibrating-wire sensors, requires approximately 64 s to acquire data.

  6. The AVW200 must be wired directly to the datalogger via a cable.

    The AVW206, AVW2011, and AVW216 have built-in spread-spectrum radios tuned to different frequencies that allow the datalogger to communicate with a remote AVW device through an appropriate radio link.


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