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A pair of divergent air-coupled capacitive ultrasonic transducers (CUTs) with curved backplates is studied to acquire signals through regions of air containing solid objects, air flow and temperature fields. Findings observed that when imaging temperature and flow fields, the aliasing artefacts were invisible, but the reconstructed values decreased with the size of dataset used, while the different filters gave the best compromise between image noise and reconstruction accuracy.

A study was conducted to analyze a pair of capacitance-type air-coupled ultrasonic transducers that were capable of operating in air at temperatures between 500 to 600 degrees C. The devices were utilized to monitor the pyrolytic removal of organic binder from injection molded silicon nitride ceramic components. Results indicated that the ultasonic velocity and signal amplitudes can be used to observe changes in the mass of the injection molded ceramic.

An air-coupled piezoelectric transducer enables the detection of ultrasonic transients from a pulsed laser source in metal and fiber-reinforced polymer composite materials. The transduction system is suitable for detecting Rayleigh waves in solid surfaces, longitudinal waves in bulk materials and Lamb waves in thin plates. The transducer is relatively sensitive to all three wave modes and displays the displacement pattern on the sample surface after laser pulse generation.