Water quality. Biological classification of rivers. Guidance on the interpretation of biological quality data from surveys of benthic macroinvertebrates— 16 стр.
Polymeric insulators for indoor and outdoor use with a nominal voltage greater than 1000 V. General definitions, test methods and acceptance criteria— 38 стр.
Polymeric insulators for indoor and outdoor use with a nominal voltage greater than 1000 V. General definitions, test methods and acceptance criteria— 38 стр.
Composite hollow core station post insulators for substations with a.c. voltage greater than 1 000 V and d.c. voltage greater than 1 500 V. Definitions, test methods and acceptance criteria— 28 стр.