Insulators for overhead lines with a nominal voltage above 1000 V. Ceramic or glass insulator units for a.c. systems. Definitions, test methods and acceptance criteria|Ceramics, Alternating-current power transmission, Formulae (mathematics), High voltage, Overhead power-line fittings, Testing conditions, Pin insulators, Impact testing, Type testing, Flow charts, Cyclic loading, Leakage paths, Acceptance (approval), Electric power transmission lines, Mechanical testing, Thermal-shock tests, Overhead power lines, Glass, Quality assurance, Environmental testing, Classification systems, Galvanizing, Electric insulators, Electrical testing, Electrical insulation, Visual inspection (testing), Dimensional measurement