You will need an “ industrial “ type sensor, plus a decent specification based on what you really need to measure .
I think I’d google this to see what’s available. Hobby gear won’t do it .
Sound moves through water about 4x as fast as through same temperature air, ~1500 m/s vs ~343 m/s.
When I look at fishing sonar sites they do claim to show "structure" to some detail and their outputs display that. You want to find the deep pockets and avoid water too shallow to boat in. From the looks at least one uses multiple transducers.
They aren't so much checking depth as mapping the bottom in 3D.
kurniaaji:
the depth of the river assumed unchanged
correct like flood, but if the monitor monitor floods viewed with a broader perspective, this was the height of this otherwise we see about the depth of the river.What sensors that can be used for water from the beginning I ask. whether with MB1030 LV-EZ3 MaxSonar-can be used in water? I've tried hc 04 and jsn 04srt did nohttps://www.rapidonline.com/Electronic-Components/Underwater-ultrasonic-transducer-200KHz-plastic-case-35-1810/t work out well
you are looking at devices that are used for air. not water.
Prowave200L is more like a fish finder and is for use underwater.
I was asking because most people only want to now how high the water level is. After a rain, for floods or when the tide changes.
To measure the depth of the water is much different, and for different needs.
If you put an ultrasonic on a bridge, and use a stick to measure the depth, you can easily calibrate any of the ultrasonic distance (in air) distance sensors. To know the water level, and then calculate the water depth to the bottom.
Since the bottom of a river does not change often, this is a very common way to know the river height.
To know the bottom from a fixed point. and not be concerned with the height of the water, you could mount the sensor underwater at a fixed point that is below the lowest water level. this would never measure the water height, only the distance from that point to the bottom. if you wanted to know the water height, you could use the much easier ultrasonic sensor that is mounted above the highest point of water and then measure the height of the water. it would be easy to calibrate the two as a pair for a sensing point. that way, the air based unit would measure changes in water height from things like rain or tides, and the bottom sensor would measure if the bottom changes from erosion.
Since you want to know the water depth I would highly recommend you google depth finder Arduino.
then ignore all the hits that confuse water depth with water level and look at the ones that are for fish finders.
get a sensor that is designed for water depth for use on a boat.
something like RayMarine
If you don't mind spending >50$ you could use a pressure sensor.
Search for "Water Level Transmitter Level Transducer Sensor" on Ebay.
They are very reliable and often used in professional installations.