Patent ID: 7912386

Claim:
A method of determining a charge to mass ratio, and a concentration, of a mixture including a first component and a second component, the method comprising: measuring a base resonance frequency of a sensor in an unloaded state; loading the mixture on a vibrating element of the sensor; measuring a first resonance frequency of the loaded sensor; removing the second component from the vibrating element of the loaded sensor, leaving the first component; measuring a second resonance frequency, and a first charge, of the sensor after removal of the second component; calculating a mass of the second component based on a difference between the resonance frequency of the sensor loaded with the first and second components and without the second component; removing the first component from the vibrating element of the sensor; calculating a mass of the first component based on a difference between the resonance frequency of the sensor loaded with the first component and without the second component, and the unloaded sensor; calculating a charge of the first component based on a difference between the charge of the sensor loaded with the first component and the unloaded sensor; and calculating the charge to mass ratio, and the concentration, of the first component based on the calculated mass of the first component, the calculated mass of the second component, and the calculated charge of the first component.