An eddy current array, in its simplest form, is a series of single elements arranged in a row, allowing users to cover a larger area in a single pass than conventional, single-coil probes (i.e., pencil probes using ECT). However, this could lead to suboptimal results. That’s why ECA probes use multiplexing.
Multiplexing involves activating and deactivating coils in specific sequences to leverage the probe’s width. Multiplexing also minimizes the interference between coils in close proximity (mutual inductance) and maximizes the resolution of the probe. ECA probes effectively eliminate the raster scanning necessary when using ECT pencil probes. This has a significant impact on inspection speeds.