Transducer Beam Width - Simrad EQ33 Manual

EQ33 Principles of operation Chapter 8-3

8.3 Transducer beam width

The transducer mounted to the hull of your vessel serves as both a 'speaker'
when transmitting, and as a 'microphone' when the echosounder is receiv-
ing. Similar to the way a flashlight focuses light, most of the sound from your
transducer is focused downwards with a smaller amount going out to the sides.
The amount of focusing of the sound beam is expressed as a 'beam width'.
Transducer
Approximation of the sound
pattern below the transducer
This angle is the transducer's
beam width
1/2 maximum intensity
Maximum intensity
Fig. 3 A representation of a transducer beam width.
The center of the sound beam is the most intense, then as you move out
towards the sides of the sound beam there is a point where the intensity of
the sound is half what it was in the center. The distance moved is the 'beam
width'. See Fig. 3.