| 摘要 |
<p>Level in which the air bubble (4) is adjustable with respect to the surface to be measured (30), by means of an adjusting element (28) inside the casing (24). The adjusting element (28) has, for that purpose, at least one adjusting screw (44, 46, 48) the coned or tapered end (42) thereof bears on a coned o tapered edge. This edge is either on an envelope (20) surrounding the air bubble or on a supporting piece (66, 68, 70, 72, 74) fixed at the end of the chamber containing the air bubble or on this vitreous chamber itself. An elastic element (51, 53) is placed on the opposite side of the contact point of the adjusting screw with the coned or tapered edge (40). This elastic element allows to limit the magnitude of the displacement force of the adjusting screw.</p> |
