scope:

The purpose of this report is to present a suggested test procedure for measuring th, radiated electromagnetic interference (EMI) emanating from rail transit systems. This report points out that, unlike inductive and conductive EMI, radiated EMI has I not been known to adversely affect the safety or reliability of rail transit operations. However, radiated interference from a rail transit system could potentially affect the neighbors of a rail transit system. It is indicated that testing rail systems for EMI poses unique problems not covered by existing EMI testing standards. The MIL-STD 461B and 462 describe in detail the testing of pieces of electrical equi] ment and vehicles sitting at rest in electromagnetically shielded enclosures essentially at arm's length. Other existing standards delineate procedures for testing equipment at greater distances out-of-doors, but still at rest. However, subway trains are large and must be tested while in motion. The suggested test procedure presented in this report describes standard physical and operational configurations for testing, along with recommended measuring equipment capable of rapid and automated data acquisition and analysis. The procedure has built-in steps to document the limits of accuracy and validity of the data obtained. The procedure presented in this report is generally consistent with procedures that have been used in the past to characterize radiated EMI from rail transit vehicles, but has been designed to provide greater consistence and speed in test performance and data interpretation