The document provides a comprehensive overview of echo sounders, which are devices used to measure water depth by sending sound pulses and measuring the time taken for echoes to return. It discusses the working mechanism, key components such as transducers and recorders, and factors that affect accuracy, including temperature and salinity variations. Additionally, the document highlights potential errors in measurements and includes a bibliography for further reference.

1. JOEL JACOB 21
SIROSH PRAKASH 40

2. OBJECTIVE
What is echo sounder
Working of echo sounder
Components
errors

3. TABLE OF CONTENTS
 What is echo sounder
 working of echo sounder
 Components
 Transducer and placement
 Recorder
 bibliography

4. What is an echo sounder
 Device used to measure depth of water
 short pulse sound energy transmitted
vertically down
 Time taken for it to echo back is used to
determine depth
 Time taken (t ) = (2 x d) / v or d =(v x t)/2
 Factors affecting echo sounder : Temp of water
, pressure ,salinity

5. WORKING OF ECHO SOUNDER
(Marinegyaan.com)

6.  Recorder sends pulse to pulse generator, it creates
electrical pulses (frequency vary)(5-600 hz)
 Through transmitter pulses passed on to the
transducer which convert electrical to sound pulses.
 These pulses travel to the bottom of the sea and are
reflected back to the transducer
 Transducer converts sound energy back to electrical
and sends it to receiver
 It is received ,amplified and sent to recorder
 The recorder records the obtained data

7. TRANDUCER
 Works on magnetostriction effect, to produce pulses
 it Change length when placed in magnetic field
 Placed in an AC field, causes vibrations, sound pulses
created
(Marinegyaan.com)

8. Placement of transducer
 Must be away from
 noises and vibrations(aft)
 Bow waves, aeration & bubbles , turbulence causes
 Placed 1/4th L from aft
 Echo sounders(ipad).mp4
(Marinegyaan.com)

9. RECORDER
 It records data obtained from the transducer
 IMO regulations require that hard copied of
recordings to be kept on board
 Thus stylus and paper usually used
(Meted.ucar.edu)(California digital library)

10. ERRORS
 Change in velocity of sound due to salinity changes of
seas
 Bubbles and aeration causes errors
 Multiple echoes in shallow waters
 Pythagoras error and slanted distance
(cram.com)
(Seafloor.otterlabs.org)

11. CONCLUSION
 Definition and uses of echo sounder
 Its working and components
 The errors associated with its calculations

12. BIBLIOGRAPHY
 marinegyaan.com
 YouTube