Modern electric railway vehicles are faced with the challenge of achieving electromagnetic compatibility (EMC) compliance with railway signaling systems. Currently, no established countermeasures or design methods that guarantee passing the EMC compliance test are available. Therefore, the enhancement of EMC management during vehicle manufacturing processes is imperative. This study devised a pre-accreditation method to be implemented at the vehicle completion stage, prior to the EMC compliance test. The proposed method entails the substitution of real ground signaling devices, whose parameters are difficult to obtain, with unified coils. The effectiveness of this approach is validated by observing whether the gain difference remains consistent when using both an exciting coil and a test train. To illustrate this method, we selected the platform screen door (PSD) balise as a representative signaling device, which is widely utilized in various railway stations. The unified coil employed in this study can be easily fabricated. First, we measured the gain difference (the ratio between the induced voltage of coils and the exciting coil current) between the PSD balise and unified coil. Next, we measured the unknown magnetic flux induced by an 8-car electric multiple unit test train by utilizing the PSD balise and unified coil. Finally, we calculated the measured difference between them. The gain and measured differences properly agreed (within 6 dB) across a wide frequency range of 200 kHz to 4 MHz.