21 March 1989 Ultrasonic Sensor For Measuring Surface Roughness
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Proceedings Volume 1009, Surface Measurement and Characterization; (1989) https://doi.org/10.1117/12.949180
Event: 1988 International Congress on Optical Science and Engineering, 1988, Hamburg, Germany
Ultrasonic reflectance/scattering measurements have been made on metal samples possessing a large range of surface roughness values. The root-mean-square roughnesses Rq ranged from 0.3 to nearly 40 µm on the mostly periodic surfaces. The echo amplitude from short incident pulses of ultrasound in the frequency range of 1 to 30 MHz was used, in the manner of a comparator, to measure relative roughnesses with an area-averaging approach defined by the ultrasonic beam spot size. Ultrasonic wavelengths ranged from about 50 to 300 µm at these frequencies, and the beam spot sized varied from 0.2 to 5 mm in diameter. Both air and fluid coupling techniques were used between the sensor (transducer) and surface, on both static and rapidly (in excess of 5 m/sec surface speed) moving parts. On static surfaces, a resolution of better than 1.0 µm Rq was achieved at the higher ultrasonic frequencies. By focusing the ultrasonic beam at 30 MHz, a profilometry capability was demonstrated on a 1 µm Rq sinusoidal specimen of 800 µm wavelength.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
G. V. Blessing, D. G. Eitzen, "Ultrasonic Sensor For Measuring Surface Roughness", Proc. SPIE 1009, Surface Measurement and Characterization, (21 March 1989); doi: 10.1117/12.949180; https://doi.org/10.1117/12.949180

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