| 摘要 |
<p>An air bubble level is used to check or measure the deviation from the horizontal of a plane face. It can also check or measure deviation from the vertical or any angular reference. The level has a case (1) and two sliding arms (2, 3). On the upper side (5) of the case (1) there is an air-bubble tube to indicate deviation from the horizontal. A second air-bubble tube (20) at one end of one (3) of the sliding arms (2, 3) is used to indicate deviation from the vertical. The case (1) has a graduated scale on its lower side (4). The sliding arms (2, 3) also have graduated scales (22). The level case (1) and arms (2, 3) are made of clear plastics material. It also has a reflecting face near the air-bubble tube to measure angular deviation.</p> |
