| 摘要 |
PROBLEM TO BE SOLVED: To provide a spirit level capable of horizontal measurement of a plurality of measurable faces solely by itself.SOLUTION: In a spirit level, sides of rectangular ring-shaped grooves 3A, 3B, 3C and 3D each having a central part curved outward are formed in a transparent base 1, each side of the grooves 3A, 3B, 3C and 3D in the base 1 is caused to form a hollow by integrating respective faces forming the respective sides of the grooves 3A, 3B, 3C and 3D and a back plate 2 of an opaque material by adhesion, and liquid and bubbles are sealed into this hollow. The grooves 3A, 3B, 3C and 3D are so configured as to make inner side side-walls of their sides orthogonal to a rear face of the base 1, while sectional shapes of outer side side-walls of the grooves are configured to be arcs each centering on an open end of the inner side side-wall and to intersect with the inner side side-wall at a bottom. |
