Using the vertical wheel of a theodolite as a spirit level and devices for defining slope testing

New measuring devices which appear in geodetic equipment that are used to measure small inclination angle i.e. Nivel 200 from Leica or box and pipe levels which help to set auxiliary geodetic devices and electronic devices (prototype) for defining inclination are subject to periodical control. They are run on a level examiner which mainly defines level ascendancy, error of middle position of the level's bubble, influence of ecological changes and measurement range. The solutions to examinations of level very often are of a prototype character (secured by a patent). Manufactured ones are quite expensive and have a character of laboratory devices.