| 摘要 |
<p>A method for identifying a change in the composition of a liquid, comprising the steps of applying a time varying electrical or electromagnetic input signal to the liquid in a range of frequencies encompassing a resonant frequency of an electrical circuit comprising the liquid; measuring an impedance quantity of the electrical circuit comprising the liquid by means of the output signal as a function of the frequency of the time varying electrical or resonant frequency input signal in said range of frequencies; determining a resonant frequency of the electrical circuit comprising the liquid; after a change in the composition of the liquid, measuring variation in the impedance quantity at or near to the previously determined resonant frequency of the electrical circuit comprising the liquid; and relating the variation in the impedance quantity at or near to the resonant frequency of the electrical circuit comprising the liquid to a change in the composition of the liquid.</p> |
