The water level meter is the most accurate method to measure the water level and well depth, which is usually used to measure the water level and well depth in wells, boreholes and water level pipes, and is especially suitable for the observation of groundwater level in hydropower projects or the manual inspection of the dam infiltration line of earth-rock dams. This instrument can be used during construction, but also as a long-term safety monitoring of the project, in line with the technical specifications for earth-rock dam safety monitoring.