Unbreakable spirit level

摘要

To fabricate an unbreakable spirit level, two essential features were applied together: 1. The glass tube filled with fluid is embedded in a bubble level receptacle with a permanently elastic transparent substance which can also absorb strong shocks and protects the tube from damage. 2. The bubble level receptacle is mounted in the spirit level body in such a manner that a plastic compound, which is viscously filled in and then hardens, shields the entire body (= bubble level receptacle) in the case of the horizontal bubble level in the hollow section and, in the case of the vertical bubble level, comes to rest at least partially against the bubble level receptacle and bonds to the latter, in which arrangement the filling compound in the hollow section must take up the complete width of the section. By combining the two measures, the spirit level is unbreakable to such an extent that it does not break and does not shift during a fall from, for example, 5 m height onto a stone floor.