The AVW200 interface module applies a new method for measuring a sensor's frequency. The AVW200 eliminates the problem of incorrect readings due to noise sources. The noise problems are overcome by an advancement in technology and mathematical processing, resulting in frequency-based measurements—a complete departure from previous time-domain-based measurements.

Features

The spectral-analysis approach analyzes the response of the wire as a function of frequency. Because we are trying to determine the resonant frequency of a tensioned wire, it makes sense to analyze the response of that wire as a function of frequency, rather than time. The approach applies a Fourier transform to the sampled response to move it from the time-domain to the frequency domain. By identifying the frequency of the peak response in the resulting spectrum, we have identified the resonant frequency of the wire.

With the data converted to the frequency domain, the sensor's resonant frequency can be determined even in the presence of external noise. Spectral analysis allows us to distinguish the sensor’s response from the noise.

Specifications

Number of Virbrating Wire Sensors Measured: Up to 2 vibrating wire sensors can be connected to the interface. Additional sensors can be measured by using an AM16/32-series multiplexer.
Power Requirements: 9.6 to 16 Vdc
Typical Current Drain @ 12 Vdc: ~0.3 mA (quiescent); ~6 mA (active RS-232 communication); ~25 mA (measurement)
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 datalogger 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 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 Standard to which Conformity is Declared: IEC61326:2002

Producing Area:USA