| 摘要 |
<p>An improved level vial comprising a cylindrical vial containing a fluid and a straight member. The straight member has a specific gravity less than the specific gravity of the fluid, a length less than the inside diameter of the cylindrical vial, and a thickness less than the inside depth of the cylindrical vial. The cross section of the straight member could be circular or square or rectangular. The ends of the straight member could be curved or pointed. There could be a transverse scribe mark on the straight member. Further the center of the straight member could be pivotally attached to the center of the vial. A level made with this improved level vial includes a frame having at least one plane measuring surface and at least one side at right angles to each other. The frame also includes a level indicating mark on the side.</p> |
