Floating ball magnetic type self-closing liquid level meter and method for measuring liquid level of light hydrocarbon in liquid storage tank

The invention provides a floating ball magnetic type self-closing liquid level meter and a method for measuring the liquid level of light hydrocarbon in a liquid storage tank, the liquid level meter comprises a liquid level pipe, a guide cylinder and a float bowl which are sequentially connected from top to bottom, a first liquid inlet hole is formed in the upper portion of the guide cylinder, a second liquid inlet hole is formed in the float bowl, and the aperture of the second liquid inlet hole is smaller than that of the first liquid inlet hole; a magnetic plugging assembly and a floating ball are arranged in the buoy, a magnetic piece matched with the magnetic plugging assembly is arranged at the bottom of the guide cylinder, the floating ball is located at the bottom of the buoy, and the magnetic plugging assembly is used for moving upwards to plug the first liquid inlet channel under the buoyancy action of the floating ball. When the liquid level is measured, after liquid enters the first liquid inlet h