which sensor will be suitable for detecting water level

[Sahan Shrestha]

which sensor will be suitable for detecting water level of a large reservoir

 

[jiripolivka]

which sensor will be suitable for detecting water level of a large reservoir

You have many choices. The simplest and most reliable is a floater, with many options to signal its position- a simple contact, a magnetic sensor, a photo-sensor.
You can use ultrasonic sensor, also are available microwave "radar"sensors.
Take whatever you feel is suitable in your conditions.

 

[FvM]

I believe that the available options are already discussed in the rich choice of similar threads linked at the bottom of this page.

Hydrostatical pressure measurement using an immersed pressure sensor ist still the standard method for continuous level measure.

 

[Sahan Shrestha]

i find microwave radar sensor of different types. the water level of 4-6 m depth is to be calculated. Which microwave radar sensor will be suitable if you have any idea?

 

[FvM]

Radar sensors (using FMCW method) are one of the more expensive solutions. They are not actually measuring the water depth but the distance to the water surface from the tank top.

Which sensors (manufacturer, type) are you looking at?

 

[John Mossbacher]

Depends on the structure of the reservoir. If it can be easily accessed, any of the previously mentioned standard sensors would do the trick but if you are looking for something more high-end for a reservoir that is difficult to read, I would suggest a remote gauge that can be linked to a smartphone. Check the Robotics Surplus page.