Length – the base of structure of space and objects.

Measurement of geometrical quantities accompanies the humanity since its origin during the whole history. One can say, that in many cases the accuracy of geometrical quantities defines the level of development of science and technology. Nowadays high-precision measurements of geometrical quantities in the wide range are required: from microcosm (nanotechnologies) to universe (study technologies and cosmos reclamation).

The level of providing the unity of measurements of geometrical quantities is not only necessary for normal functioning of the modern scientific and technical level of economy but also defines the output quality, technical and ecology safety in the country.

Providing the unity of high-precise measurements of geometrical quantities is especially required in such fields: defense equipment (location and range finders); precision machine building, aircraft building and aerospace equipment (dimensional measurements, measurements of surface roughness), ecology monitoring and safety (measurements of crustal movements and complex engineer and technical installations); geodesy and cartography (attestation of range-finder apparatus, instruments for geodesic application, receivers of satellite navigation system); modern nanotechnologies (measurements of nano-objects parameters and providing of probe positioning of technological equipment); scientific research (measurements during the conducting of unique physical experiments).

During the realization of the system of unity measurements providing in the field of geometric quantities which includes the appropriate standards, verification schemes and other normative and technical documents, special attention is paid on the creation of the measurement unit - meter and head the transfer system of its size to the lower levels of metrological assurance.

As it’s known the General Conference on Weights and Measures adopted in 1983 the following definition of meter: “The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second”. According to this definition the speed of light is postulated to be exactly equal to 299792458 m/s, and the carrier of the length unit is laser, the source of light radiation. In the national primary standard of Ukraine DETU 01-03-98 the length unit is reproduced exactly by means of this definition.

In due time, the value of the speed of length was obtained experimentally at NSC “Institute of Metrology”, and it was recognized to be one of the most precise in the world, it entered reference books and value tables of physical constants and it’s practically gone down in history of world science.