A general method was established for precisely measuring velocity dispersion and attenuation in solid specimens with acoustic losses in the very high frequency (VHF) range, using the complex-mode measurement method and the diffraction correction method. Experimental procedures were presented for implementing such a method and demonstrated this measurement method in the frequency range of 50-230 MHz, using borosilicate glass (C-7740) as a dispersive specimen and synthetic silica glass (C-7980) as a nondispersive standard specimen. C-7980 exhibited no velocity dispersion; velocity was constant at 5929.14±0.03 m/s. C-7740 exhibited velocity dispersion, from 5542.27 m/s at 50 MHz to 5544.47 m/s at 230 MHz with an increase of about 2 m/s in the measured frequency range. When frequency dependence of attenuation was expressed as α = α0fβ, the results were as follows: α0 = 1.07 × 10-16 s2/m and β = 2 for C-7980 and α0 = 5.16 × 10-9 S1.25/m and β = 1.25 for C-7740.
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics