Low-voltage switchgear and controlgear assemblies. Part 3. Particular requirements for low-voltage switchgear and controlgear assemblies intended to be installed in places where unskilled persons have access for their use. Distribution boards
State system for ensuring the uniformity of measurements. Transfer units of time, frequency and time scale national UTC(SU) from the State primary standard of the Russian Federation with the use of the GLONASS system. Classification. Measurement uncertainty and error. Normalized metrological characteristics
