NorthStar Navigation 491 - Manual (Page 33)

491 INSTALLATION MANUAL Revision A PAGE 29
Glossary
cavitation The formation of bubbles, which may negatively impact a transducer’s
readings by reducing its ability to put energy into the water.
deadrise The rise of the bottom of a vessel above a horizontal line at the center of
the vessel; that is, the slope of the hull away from the horizontal.
echo sounder An instrument that uses sound waves to measure the depth of a body of
water or an object (such as a school of fish) below the water’s surface.
fairing block A block used to create a horizontal surface for mounting a thru-hull
transducer when the vessel’s deadrise is more than 5 degrees.
transducer The device mounted through the hull to send and receive ultrasonic
beams that determine seabed conditions and locate fish. Essentially, a
transducer is an energy converter, which changes electricity to sound
(send) and sound to electricity (receive).
water column An imaginary column through the water created by the path of a single
transducer ping and its echoes.