DUAL QUARTZ-CRYSTAL MICROBALANCE OSCILLATOR CIRCUIT - MINIMIZING EFFECTS DUE TO LIQUID VISCOSITY, DENSITY, AND TEMPERATURE

A novel dual oscillator circuit for quartz crystal microbalance studies is described. It permits direct measurement of resonant frequency differences between two AT-cut quartz crystals both having one face in contact with a liquid. The circuit yields accurate and precise frequency difference data in diverse liquid media of widely differing viscosity, density, and conductivity. This circuit can be applied to quartz crystal microbalance and electrochemical quartz crystal microbalance studies in which variation of these solution properties occurs.