1. Introduction VT USA-268A and VT USA-268B are PC-based
real-time underwater sound analyzers with
ultra-low noise and a huge
dynamic range, covering 9 Hz to 92 kHz (-3 dB), powered by the
comprehensive virtual instrument software Multi-Instrument®.
Each analyzer includes a high-sensitivity hydrophone with a built-in
preamp and an XLR output connector, plus an XLR-to-USB audio
interface. The hydrophones can withstand a static water pressure up to 350 m and drive cables up to 250 m with negligible signal
degradation.
The hydrophones in the two analyzers are
manufactured with the same industrial-grade sensors under strict
quality control, making them well-suited for absolute underwater sound
level measurements in marine and industrial environments. The hydrophone of VT USA-268A is assembled with a 150g sliding stainless
steel weight on its cable to provide negative buoyancy and stable
positioning in mild wind and current conditions. The hydrophone of VT
USA-268B features a standard panel-mount design, making it well
suited for integration into systems, such as autonomous recording
units, autonomous or remotely operated vehicles, and dive camera
enclosures.
The XLR-to-USB audio interface used in the analyzers
has two ADCs working in tandem to create a single output data stream
in 32-bit float format. One “low gain” ADC is optimized for
high-level signals, and the other “high gain” ADC is optimized for
low-level signals. This state of the art dual-ADC architecture
provides an unmatchable dynamic range compared with the conventional
single ADC approach. It is possible to capture underwater sounds at
low levels with high fidelity and at high levels without clipping, all
without the hassle of manual analog gain adjustment.
2. Package Contents
1) Hydrophone with a built-in preamp
and an integrated XLR cable 2) XLR-to-USB Audio Interface 3) USB cable (1 m) 4) CD (contains the copy-protected
Multi-Instrument Software) 5)
USB hardkey (contains a Multi-Instrument Pro License) 6) Carrying
Case
