Is there a sensor for measuring the level of liquid in the tank?

Question

Microcontrollers

It is required to measure the water level in the tanks. Requirements:
- The height of the water column can vary within 2 meters.
- I would like to measure in a non-contact way. But not critical.
- A smooth measurement is needed, high accuracy is not required, within 5 cm is enough.
- Readings will be taken by the microcontroller.
- Requires a budget option.
Nothing but expensive industrial devices came across. I came across an ultrasonic distance meter, but they are all not tight, they are not suitable for a container.

Answer 1

Float tube and 40 optocouplers.
Tube with float-magnet and 40 reed switches.
Weight sensors under the container and recalculate weight into volume.
The weight sensor on top and the load suspended from it almost to the entire height of the tank, use the decrease in the weight of the load according to the law of Archimedes.

Answer 2

I once managed with an ordinary potentiometer with a lever to which a float is attached.

Answer 3

It is possible, as in the article about the kettle, to etch the board with pads and fill it with food grade silicone.