Technical information

EQ-55 Operators Manual 950-70017001/Iss 1.
2
Principles of Operation of an Echo Sounder Page 3.
3
Kongsberg Simrad Mesotech Ltd.
Port Coquitlam, BC - Canada
3. PRINCIPLES OF OPERATION OF AN ECHO
SOUNDER
3.1 PARTS OF AN ECHO SOUNDER
An echo sounder is composed of the display screen, processor, and
receiver/transmitter unit which in case of the EQ 55, are housed in one unit
which should be installed in an easily accessible location aboard ship.
Connected to this unit by shielded cables are the transducer(s) which are
mounted horizontally on the bottom of the hull.
3.1.1 Display Screen
The display screen presents in graphic and numerical form the information the
processor is receiving and accumulating from the transducer(s).
3.1.2 Processor
The processor is the "brains" of the echo sounder. It is sealed inside the unit
which protects it from harm. The processor is composed of highly sophisticated
microprocessor, memory and logic circuitry.
3.1.3 Receiver/Transmitter
The receiver/transmitter (often called the "transceiver") section of your echo
sounder takes it's commands from the processor. The processor tells the
transceiver to activate the transmitter. The transmitter sends a high
voltage transmit "ping" to the transducer mounted on the hull. At that point the
transmitter's job is done and the receiver takes over. See Figure 3.1
The receiver is also connected to the transducer and amplifies the very small
signals received as echoes from fish and the sea floor which arrive at the
transducer (see Figure 3.2). The receiver is designed to reject other signals as
much as possible and to provide enough amplification to see even relatively
small targets at long ranges. The amplified receiver signals are then sent to the
processor to be shown on the display screen.