Machine spirit levels provide greater accuracy than ordinary spirit levels. Due to their great sensitivity, it is important that the measurement that is made is of the same accuracy as the application, otherwise the measurements "play" too much. They are widely used for leveling machines (Milling machine, lathe, etc.) as well as axes. 0.02 mm / m means that each line of its reading corresponds to 2 centimeters of a millimeter per meter of deviation. .