The inclination plays a multifaceted role in metrology. In relation to the form and position tolerances for components, inclinations are controlled via the position tolerances, or more precisely the directional tolerance of angularity. For this purpose, in the case of surfaces, the toleranced area must lie between two planes that are inclined at the specified angle to the reference. For axes, the toleranced area must lie between two parallel planes inclined at the specified angle to the reference. The axis inclination also plays an important role in the direct handling of measuring instruments, since it can affect measuring processes as a systematic error. In this context, universal instruments are usually used for standing axis error, tilting axis error and target axis error. When dealing with leveling instruments, only the axis tilt in the direction of the telescope is relevant, which is usually compensated automatically by modern instruments. Depending on the measuring task, inclinations and angularity are measured with different, sometimes highly specialized devices. Thus, there is a large number of diverse inclinometers that are used in areas such as construction, aviation, shipbuilding or space travel, in the military or even in transportation.