Patent ID: 8413512

Claim:
A method for agitating a liquefied material using a quartz crystal oscillator in vibrating the quartz crystal oscillator at a given frequency and measuring the variation of the frequency due to a substance in contact with the quartz crystal oscillator, wherein the quartz crystal oscillator is vibrated at other frequency different from the given frequency and equal to or higher than the fundamental vibration frequency to agitate a liquid containing the substance, wherein the quartz crystal oscillator comprises a quartz crystal plate, a first electrode stacked on a side of the quartz crystal plate, and a second electrode stacked on a second side of the quartz crystal plate opposite from the first electrode, wherein the substance is in contact with the first electrode, wherein the liquid containing the substance is agitated at the fundamental vibration frequency or the sub-vibration frequency, and wherein the quartz crystal oscillator is vibrated at an Nth harmonic (N=3, 5, 7, . . . ) vibration frequency during the time of measurement.