Water level indicator is an essential one in both domestic and industrial use. Ultrasonic sensor used to detect the level of water in the tank or liquid column in the industries.
When sound waves are transmitted in environment then they return back to the origin as ECHO after striking on any obstacle. Ultrasonic sensors are used to detect the target by interpreting the reflected signals. This done by measuring the time lapse between sending a signal and receiving an echo, the distance can be measured. The sensor has two opening in the front. One sends ultrasonic waves and the other one receives the ultrasound and gives output in the electrical form. So we have to only calculate its travelling time of both sounds means outgoing time and returning time to origin after striking on any obstacle. And after some calculation, we can get a result that is the distance.
Distance= (travel time/2) * speed of sound
Where speed of sound is approximately 340 m per second.