Methods of Measuring Electromagnetic Emission from Trains

Alternative ways of recording electromagnetic emissions from trains are presented. The standard method, EN 50121 [3], where an antenna is located at a fixed position beside the railway track, has been compared to a new method, using antennas and recording equipment placed on-board the train[1]. Different instrumentation set-ups have been tested under laboratory- and field- conditions. Both electric and magnetic antennas have been mounted on trains and recordings have been made on-board, using a spectrum analyser in combination with an oscilloscope. Transient voltage peaks exceeding certain levels have been counted. Antennas mounted on a train have proved to give good data quality for long time logging, and is therefore proposed to be included in future standards. The proposed method is suitable for both transients and harmonics and provides a very economical alternative to stationary set-ups, when different train operating conditions has to be covered.