Measurement of the Instrumental Effect Caused by Flexure Clamping on Quartz Crystal Microbalances

This study focuses on piezoelectric quartz crystal microbalances (QCMs), widely used in space and military instrumentation, as fundamental components in highly sensitive mass detection devices. In this research, a proper setup was developed to investigate the relationship between clamping preload and crystal resonance, with particular attention to the effects of concentrated loads. The latter ones, not properly addressed in the literature, come from the need to safely clamp QCMs in critical environments, like those experienced during the launch of rockets or payloads. Thus, the study investigates the behaviour of piezoelectric quartz crystals (AT-cut, 10 MHz) with gold electrodes, using a QCMs’ three-pinned mounting system. Measurements showed that the effect of the preload on the frequency variation resulted in a repeatable increase in the crystals’ resonance, increasing the loading, up to three ppm more than the unloaded quartz crystal oscillating frequency.