| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a level easy to understand an inclination. SOLUTION: Three or more grooves 2 are opened at an equal angle with one point as the center on a ceiling surface of a sealed vessel 1 sealed with liquid 3 and a bubble 4, the groove bottom of the respective grooves 2 gently and lowly inclines to the tip side of the groove from a crossing part 21 of the grooves, and when measuring levelness, the bubble 4 is fitted to the grooves 2 to move or stop.</p> |
