Areas that may (some already have) benefit from using microwave NDT techniques

• Accurate thickness measurement of coatings, single dielectric slabs, layered dielectric composites made of plastics, ceramics and any other type of dielectric materials
• Minute thickness variation of each layer in these dielectric media.
• Disbond, delamination and void detection and thickness evaluation instratified media and their depth determination.
• Inspection of thick plastics and glass reinforced composites for detection of interior flaws, fiber bundle orientation and breakage, moisture content, etc.
• Detection and estimation of porosity in dielectrics.
• Impact damage detection and evaluation in reinforced composite structures including graphite composites.
• Fiber orientation determination in graphite composites.
• Accurate material/constituent characterization in dielectric mixtures.
• Detection and evaluation of curing in chemically reactive media.
• Relating electrical properties of materials such as dielectric characteristics to physical and mechanical properties such as compressive strength of concrete members.
• Detection of surface cracks (stress and fatigue) in metals including sizing of the three dimensions of a crack. This feature extends to filled and cracks covered with various dielectric coatings. These covered cracks have been shown to be detected easier than exposed cracks which can allow for crack detection under various coatings without the need for coating removal prior to testing.
• Optimization capability for all of these measurements to obtain higher measurement sensitivity.
• Production of defect images.
• Using microwaves as heat sources in thermography.
• And finally, new applications are continuously being discovered.

1. Why Microwave NDT&E:
   Zoughi, R. "Microwave Non-Destructive Testing and Evaluation," A graduate textbook, KLUWER Academic Publishers, The Netherlands, 2000.
2. Zoughi, R., "Microwave and Millimeter Wave Nondestructive Testing: A Succinct Introduction, Materials Evaluation", vol. 53, no. 4, pp. 461-462, April, 1995. Reprinted in the Research in Nondestructive Evaluation, vol. 7, no. 2/3, pp. 71-74, 1995.