PSA-900 Sonar Altimeter:

The Datasonics PSA-900 Series of programmable sonar altimeters are multi-use, precision instruments for acoustic range measurement in water and air applications.

The PSA-900 generates a narrow-beam acoustic signal and measures the travel time for the signal to bounce back from the target surface. The unit provides range data in both analog and digital formats for analysis and process control.

This microprocessor-based system automatically adjusts the receiver gain to compensate for false echoes and ambient noise. The unit is also programmed to measure water temperature and, with the addition of an optional pressure transducer, depth.

For water applications, the PSA-900 has two range options:
 

• Display range of 30 meters with a resolution of 1 centimeter and a maximum usable range of 30 meters
   
• Display range of 300 meters with a resolution of 1 centimeter and a maximum usable range of 1 meter to 200 meters, depending on local conditions.

The PSA-900 is completely self-contained and requires only external DC power between 15 and 28 Volts to operate. The unit is connected to other instrumentation through a color-coded seven-wire pigtail cable.

Standard Features

• Microprocessor control
• Analog and digital output of parameters
• Externally adjustable receiver Time-Varying Gain (TVG) to compensate for 20 Log 2R+2aR losses
• Range data corrected for changes in sound velocity
• Automatic receiver/transmitter frequency tracking
• Standard RS-232 and optional RS-422 output of parameter measurements in engineering units
• Data averaging of range readings
• Internal or external keying
• Error flagging when no data are received
• Standard output of water temperature

Applications

• ROV/Instrument altitude/depth studies.
• Sediment transfer studies
• Bridge scour studies