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
Occupational safety standards system. Respiratory protective devices. Self-contained open-circuit compressed air breathing apparatus with half mask, designed to be used with positive pressure only. Technical requirements. Test methods. Marking
