| 摘要 |
C:/RPoib/DCC/EJL/4 50897-..DOC- 8/0m2) 3 -6 A bubble vial for a spirit level, the vial having an upper wall which is curved from end-to end with a curvature which is greater within a central zone of the vial than in zones at 5 either side of the central zone, the curvature preferably being of elliptical form. The greater curvature within the central zone within which the bubble will lie in a level condition provides greater sensitivity of the vial as a level condition is approached. |
