Measurement task
Rail transit measurements may cover traction power, motor current and onboard auxiliary supplies. Operational records focus on load changes, while development testing may also require startup and switching transients. Measurement-point location, conductor size and installation conditions vary, so sensor structure and signal chain should be defined for each task.
Selection considerations
Flexible coils can measure AC within their response limits; DC tasks require sensors with DC response. Also check environmental conditions, insulation requirements and output interfaces. For existing equipment, establish the available installation space and system constraints before comparing range and frequency response.
Select separately for traction DC and motor AC
Signals in traction supply conductors and motor phase leads may differ; their shared rail application does not justify using the same probe. AC Rogowski coils can observe current waveforms within their response range. Continuous DC recording requires a measurement method with DC response. Large-conductor dimensions, existing installation positions and output cable routing are also selection inputs.
