Sensing properties of normal oscillatory modes of quartz plates

New type of an acoustic plate mode: quasi-longitudinal normal wave

“…They show that for quartz plate with free surfaces and normalized thickness H =k ¼ 1:485 the attenuation of the modes a n depends on the mode order n and the type of the liquid. For water (small viscosity) the modes ordered as n ¼ 2, 3,6,8,9,13,19,20,25,27, 29 are characterized by low attenuation a n < 10 dB and because of that they possess small vertical component U 3 . Furthermore, if compared the same modes with each other for glycerin (large viscosity), there is only mode n ¼ 6, whose attenuation is noticeably small ða 6 < 4 dB).…”

“…Finally, the sensitivity of the quasi-longitudinal mode Dv n =v n towards the partial variations of the density q, elastic moduli C ij and the plate thickness H =k is examined as in [9]. For this, each parameter of the plate is varied one by one within AE 1% from its mean value [5] holding other parameters of the plate constant.…”

“…The temperature coefficient of the delay TCD 6 is calculated as the full temperature differential of the density q, elastic moduli C ij and thermal expansions of the plate along the propagation direction a x and the plate thickness a H [9]. The as-calculated TCD 6 (20.2 ppm/°C) is proved to be very close to the same coefficient for the longitudinal bulk wave (TCD L ¼ À0:5 Á ½a x þ ð1=C 11 Þ Á ðdC 11 =dtÞ ¼ 19:7 ppm/°C).…”