This study is one of the basic experiments for the development of a weight type water level gauge. The weights are made of polyvinyl chloride (PVC) with a density of 1.1-1.35 g/cm3, in cylindrical shapes of different sizes. The weights come in different diameters: 5, 6, 7, and 8 centimeters, and two different lengths: 20 and 30 centimeters. The weight of the weights was measured using a load cell and the inverse relationship of weight change with increasing depth was investigated. Also, by adjusting the gap between the weight and the outer casing, the distance at which the error in the weight observation due to the surface tension of water of 72.75 dyne/cm (20℃) was not affected was determined. In conclusion, we found that the larger the diameter of the weight and the smaller the height, the better the correlation with the water depth. Also, considering contamination of the PVC weight and manufacturing precision, it was determined that the space between the PVC weight and the external case required more than 1cm. A buoyancy type water level gauge requires the smallest possible weight diameter and sufficient clearance.