For more than 50 years, quality control practitioners have relied upon ultrasonic techniques as a way to nondestructively gage the thickness of manufacturing materials. In the early days, these measurements often required a series of complex calculations by the users of ultrasonic measuring devices. But in recent years, relentless miniaturization in digital computing power has led to portable, user-friendly ultrasonic instruments that allow near instantaneous readings of material thickness, while also providing on-board data-logging and networking capabilities.

Now the field of ultrasonic nondestructive testing (NDT) is taking another step forward. Thanks to advances in digital signal processing software, new portable ultrasonic devices are emerging that can--for the first time--provide simultaneous thickness measurements of multiple material layers in a test piece. Additional advances enable precise gaging of extremely thin multilayers not previously measurable by ultrasonic instrumentation.