Last Updated on March 6, 2023 by You Ling
Application of Piezoelectric Ceramics in fishfinders
What is fishfinders?
A fish finder is a sonar tool that helps locate fish. Sonar stands for Sound Navigation and Ranging. Depending on the model you choose, the fishfinder can be equipped with GPS, marine radar and a compass to help you find your way on a boat or kayak. Fish finders use sound to locate underwater objects. They work by emitting sound pulses and waiting for an echo. The frequencies used vary from very low (infrasound) to very high (ultrasonic). This is the exact same way bats hunt in the air.
Fishfinders typically display the information obtained from the echo sounder on a screen in the form of a graphical representation, called a sonar display. The sonar display shows the depth of the water and the location and size of any underwater objects, including fish. Some fishfinders also use additional technologies, such as GPS and mapping software, to provide more detailed information about the location of the fish and the surrounding underwater environment.
Fishfinders are widely used by recreational and commercial fishermen to improve their chances of catching fish and to locate areas with high fish populations. They are also used by researchers to study fish populations and migration patterns.
How fishfinders works?
The fish finder consists of two main parts: the transducer and the main processor plus the display.
The transducer contains a piezoelectric crystal that is used to drop sonar pulses into the water by vibrating at a specific frequency. When these pulses encounter an object, they are reflected back to the transducer, which picks up the signals and passes them on to the main unit for interpretation. Based on the strength of the returned signal and the time it takes to travel through the water, the fishfinder can calculate the shape and location of objects that reflect the sonar pulse.
The latter is basically a small computer that processes the information received from the transducer and converts it into a digital signal on the screen.
Here’s a step-by-step explanation of how a fishfinder works:
The fishfinders sends out a sound wave, called a “ping,” from its transducer into the water.
The sound wave travels through the water and bounces off of any underwater objects, including fish, rocks, and the seafloor.
The reflected wave, or echo, returns to the transducer in the fishfinder.
The fishfinders measures the time it takes for the echo to return and uses that information to calculate the depth of the water and the location of any underwater objects.
The information obtained from the echo sounder is then displayed on the fishfinder’s screen in the form of a graphical representation, called a sonar display. The sonar display shows the depth of the water and the location and size of any underwater objects, including fish.
Some fishfinders also use additional technologies, such as GPS and mapping software, to provide more detailed information about the location of the fish and the surrounding underwater environment.
In summary, fishfinders use an echo sounder to emit a sound wave into the water, measure the time it takes for the echo to return, and display the information obtained from the echo sounder on a screen in the form of a sonar display. This information can help recreational and commercial fishermen locate and track schools of fish in the water.
Which piezo elements can be used for fishfinders?
Piezoelectric elements have several advantages for use in fishfinders, including their high-frequency response, high sensitivity, and small size. They are also relatively low-cost and easy to manufacture, which makes them a popular choice for this application.
Fish finders are typically constructed from piezoelectric elements of various shapes and sizes, depending on the application. The material for a simple sonar might be a hard piezoelectric ceramic (PZT-40). They offer high power density and high sensitivity. However, for high-resolution smart sonars, respectively, aperture synthesis is used, preferably a soft piezoelectric material (PZT-51).
