Comparing a 10 MHz thickness–shear mode quartz resonator with a commercial process viscometer in monitoring resol manufacture process

This study deals with the applicability of a 10 MHz piezoelectric thickness–shear mode (TSM) quartz resonator in monitoring of an industrial resol manufacture process. The quartz resonator is compared with a commercial process viscometer. Thirteen process batches were monitored concurrently with the two on-line instruments. At the isothermal phase of the manufacturing process, prior to process cut-off, signals from both measuring devices show measurable change in reaction rate. Correlation between the signals of the two instruments was 0.776. In all batch measurements, but one the resonator’s signal was more linear and/or less disturbed than the viscometer’s signal.