Meter-Kilogram-Force-Second System

(MkGS system), a system of units for physical quantities in which the fundamental units are the meter, the kilogram-force, and the second. It was put into practice in the late 19th century and was adopted in the USSR in OST (Sectorial Standard of the All-Union Committee on Standardization) VKS 6052 in 1933 and in GOST (All-Union State Standard) 7664–55 and GOST 7664–61, “Mechanical Units.” The choice of the unit of force as a fundamental unit brought about the wide use of a number of MkGS units (mainly units of force, pressure, and mechanical stress). The system is often called the technical system of units. The unit of mass adopted for the MkGS system of units is the mass of a body that experiences an acceleration of 1 m/sec² when a force of 1 kgf is applied to it. It is sometimes called the technical unit of mass, or the inerta: 1 technical unit of mass — 9.81 kg.

The MkGS system of units has a number of serious draw-backs: the lack of agreement between the mechanical and the practical electrical units; the lack of a kilogram-force standard; the rejection of the widely used unit of mass, the kilogram (kg), and, as a result (to avoid using the technical unit of mass), the derivation of dimensional quantities based on weight rather than mass (specific weight, weight flow rate, and so on), which some-times led to confusion of the concepts of mass and weight and to the use of the symbol “kg” in place of “kgf.” These drawbacks motivated the acceptance of the international recommendations to reject the MkGS system of units and to shift to the International System of Units.