Evaluation and minimization of experimental errors in elastic constants and internal friction obtained by the composite-bar method

Using the composite-bar method, the fundamental frequency f_sand internal friction Q^-1of a sample were measured as a function of the fundamental frequency f_qof the quartz vibrator by using quartz vibrators with different fundamental frequencies. The experimental values of f_sand Q^-1varied with f_qand were maximum and minimum respectively at f_q=f_s. The f_sand Q^-1values at f_q=f_sare the most probable values, and they were determined by interpolation of the data. The errors were 0.05 to 0.10% (practically negligible) in f_sand 20 to 300% in Q^-1, when the difference between f_qand the most probable f_swas 10%.