Quartz crystal oscillator circuit for high resolution microgravimetric sensors in fluids

Abstract

A simple oscillator circuit for high resolution quartz crystal microbalance sensors is proposed for fluid media. It can solve the working problems of standard crystal controlled oscillators in damping media. The design is adapted to the conditions of strong damping that the quartz experiences, so that the oscillation stays in spite of the reduction of the resonator quality factor. The conditions for obtaining a stable frequency according to the resonator damping and the static capacity are studied. Experimental results confirming the success ot the circuit are reported.