Patent ID: 6044702
Filing Date: 2000-04-04
Classification: G01N

Abstract:
A method for locating the bed level of settled particles within a liquid slurry comprising,transmitting ultrasonic sound waves into a slurry of particles to generate echoes from said particles,generating first analog electrical signals from said echoes,multiplying said first analog electrical signals by any of sine or cos signals to produce second analog signals,generating digital electrical signals from said second analog signals,processing said digital electrical signals to identify a bed level of settled particles by Doppler method comprising the steps of:selecting a number of depths in the slurry for investigation;dividing said first analog signals from said echoes into sine and cosine channels;multiplying the signals in the sine channel by a sine signal of the same frequency as the ultrasonic sound wave;multiplying the signals in the cosine channel by a cosine signal having the same frequency as the ultrasonic sound wave;converting the signals in each of the sine and cosine channels to said digital signals; andintroducing the digital signals in the two channels to a spectral analyzer algorithm.