| 摘要 |
<p>The measurement device is suspended by its cord at two cord supports on the same level. The cord fastening devices can be so designed, that when put together they form a chamber in which the level can be placed when not in use. The whole device can be tied up by the cord into a small packet which can be used, together with its own cord, as a plumb bob. Suspension strips of the unit have a cord hole or one has a cord hole and the other a hook, with an automatic protection against falling off. At least one of the cord supports has a built-in vertical level, and the two cord supports can be shaped differently.</p> |
