说明：  国际标准，需要收费的，现贡献给大家。站长不用修正说明，想要的只要一搜到50121的标准号就会下，根本不会看说明，不想要的看了说明也不会下。 Railway applications - Electromagnetic compatibility Part 1: General
(The railway EMC set of product-specific European Standards is intended, in the main, to permit compliance with the EMC Directive, but also to provide a means of prescribing compatibility between internal parts of the railway. It consists of five parts described at the end of this introduction. )