Properties of the overtone mode of the quartz crystal microbalance in a low-viscosity liquid

The effect of the immersion angle on the overtone mode of the quartz crystal ‘microbalance’ (QCM, piezoelectric quartz crystal) was investigated in a Newtonian liquid. The measurement using the impedance analyzer revealed that the resonant frequency shift of the Nth overtone mode of the QCM was depend on the immersion angle, and, at each immersion angle, was (square root)N times larger than that of the fundamental mode. These tendencies were also observed in the resistance of the Butterworth–Van Dyke equivalent circuit. Furthermore, on the basis of these results, we have discussed the immersion angle dependence of the resonant frequency shift and the resistance.