My problem is that I need a sensor which is used to find the river bed depth. I tried using ultrasonic sensor(hc-sr04) placed in air medium, the signal reflects at air-water interface, working just like level detector. So I decided of placing the sensor in water to serve the purpose.
Can I place the sonar or ultrasonic sensor in water with waterproofing?
Will it give a solution to my problem?
Please help me to arrive a solution. Thank you.
No, any measurement sensors that are made for air will not work in water. You have to realize that sound travels differently through water. You need to find a water specific sensor that has logic level output. Then write code for it. I would think that other people have done this so search Google and see what you find.
Complete devices that work in the same way as the HC-SR04 are sold fairly cheaply to boaters as “fish finders” or depth sounders. The underwater transducers are undoubtedly available separately.