| 摘要 |
PROBLEM TO BE SOLVED: To provide a level for drilling or tapping orthogonally to the face to be processed simply and accurately with a small-sized electric drill or the like. SOLUTION: A cylindrical or hollow observation part 5 having the inner diameter of 5-10 mm and the height or the depth of 5-10 mm is disposed on the center part so as to view the bubble position accurately from the just above side in order to confirm the bubble position in liquid in a bubble holding part 3 of the level body 2. In addition, accuracy of horizontality and/or verticality can be heightened simply and inexpensively by sticking a transparent plastic or a glass cover sheet 4 having the thickness of 5-10 mm on the upper surface of the bubble holding part 3 of the level body 2. COPYRIGHT: (C)2005,JPO&NCIPI
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