The main advantage of the total focusing method (TFM) is in the name. The entire TFM zone is focused, not merely a focal point at a certain depth like conventional phased array (PA). Despite its appeal, the prohibitive aspect of TFM for PA inspectors has been slower data collection and processing. Historically, it was slower than conventional PA because TFM requires full matrix capture (FMC) data acquisition, which collects a much larger volume of elementary data. Then all that acquired data must be processed to achieve total focusing in the TFM zone. However, as manufacturers of nondestructive testing (NDT) technology invest in TFM research and development, FMC data collection and TFM processing capabilities advance. With improvements to TFM technology, more users of conventional PA are showing interest in incorporating the method into their procedures.
With this rise in popularity of TFM technology comes growing demands for better signal representation and even faster data acquisition. Several tools have been introduced that accelerate FMC data collection, but the increase in speed often comes at the expense of signal quality. How can you move the probe faster? Simple! Collect fewer data, right? Although faster, this economizing at the data collection stage has a direct impact on the quality of the generated TFM image. For years, the industry has strived to produce technology equally capable of acquiring FMC data at fast acquisition rates and generating an optimal TFM image without sacrificing signal quality.