Patent ID: 8539812
Filing Date: 2013-09-24
Classification: G01N

Abstract:
1. A method of detecting bubbles comprising: sending a first ultrasonic signal through a fluid path by an ultrasonic transmitter, the signal corresponding to a first range of ultrasonic frequencies; reporting a detected signal by an ultrasonic receiver; selecting an internal receiver signal reference; determining the amount of time the detected signal exceeds the internal reference; and calculating bubble size based on the amount of time the detected signal exceeds the internal reference; determining a resonant frequency based upon the detected signal from the first range of ultrasonic frequencies; storing the resonant frequency; sending a second ultrasonic signal through the fluid path by the ultrasonic transmitter, the signal corresponding to a second range of ultrasonic frequencies surrounding the resonant frequency; resending the first ultrasonic signal after a degradation in the detected signal is detected from sending the second ultrasonic signal; and redetermining the resonant frequency based upon the detected signal from the resending of the first range of ultrasonic frequencies.