The new AVW200 2-Channel Vibrating-Wire Spectrum analyser interface module, available from Campbell Scientific Aust , applies a new method for measuring the sensors frequency. The traditional method uses a time-domain approach.
The natural or resonant frequency at which the wire is oscillating is determined by exciting the wire with an AC excitation, stopping the excitation and then measuring the time between response pulses.
Campbell Scientific Aust also have the optional AVW211, which incorporates an inbuilt spread-spectrum radio for wireless communications. With a 920- to 928-MHz frequency range, the AVW211 is suitable for Australia and Israel.
The features of the 2-Channel Vibrating-Wire Spectrum analyser include:
- Reduces the measurement error due to noise
- Provides low current drain (300μA quiescent, 40mA during two second measurement)
- Resolves the vibrating -wire measurement to less than 0.001 hertz (Industry standard hertz)
- Optional inbuilt spread spectrum radio
- Uses SDI-12, serial output or PakBus network protocol to retrieve the frequency of interest
- Includes dual channel coils plus thermistor
- Allows multiplexer control (requires AM16/32B)
- Uses simplified programming
- Supports standalone capability with optional wireless interface
- Program Execution Interval: 1 second
- Memory: Either 128 or 512 kb of SRAM; 2 MB of OS Flash
- Voltage: 9.6 to 16 Vcd
- Size: 21.6 x 11.18 x 3.18cm
- Weight: 430g