| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic transducer that exhibits white bait detection capacity and white bait identification capacity with the minimum number of oscillators, can facilitate repair, replacement or the like of the oscillators, can be manufactured at low cost, in fishing white baits performed while a ship travels at about 20 knots. <P>SOLUTION: Three oscillators for generating a frequency of about 200 kHz suitable for white bait detection and one oscillator for generating a frequency of about 50 kHz for wide finding are fixed so that ultrasonic beams go right downward, left downward, and just downward with respect to the hull, and are mounted inside a storage body filled with insulation oil in one horizontal length 1 column with respect to the travel direction. One oscillator for generating a frequency of about 400 kHz is additionally mounted just downward with respect to the hull, thereby increasing the reliability of white bait fishing. Adding two oscillators for generating a frequency of about 50 kHz further widens the finding range. <P>COPYRIGHT: (C)2007,JPO&INPIT |
