| 摘要 |
PURPOSE:To enable the indication of positive and negative gradients by enclosing a steel ball in a bubble tube shaped in a fourth circular arc. CONSTITUTION:A steel ball 6 and an air bubble 3 are enclosed together in a bubble tube 2. While the air bubble 3 is in a saturated state in the topmost part, the steel ball 6 is located in the lowermost part of the circular arc of the inner surface of the tube under the effect of gravity, indicating the degree of a negative gradient. Thus, any gradient can be measured. |
