Ultrasonic particle size measurement apparatus

Claim 1

APPARATUS FOR PARTICLE SIZE ANALYSIS COMPRISING: A SEDIMENTATION VESSEL WHEREIN AN AGGREGATE OF SMALL PARTICLES SUSPENDED IN A LIQUID MAY BE SPATIALLY DISTRIBUTED ACCORDING TO WELL KNOWN SEDIMENTATION PHONOMENON; A PULSED OSCILLATOR HAVING ELECTRICAL SIGNALS OF AN ULTRASONIC FREQUENCY; A TRANSDUCER FOR TRANSMITTING ULTRASONIC SIGNALS THROUGH A SECTION OF THE SEDIMENTATION VESSEL IN RESPONSE TO THE SAID PULSED OSCILLATOR SIGNALS; MEANS FOR DERIVING A FIRST D.C. VOLTAGE, THE VALUE OF WHICH IS PROPORTIONAL TO THE AVERAGE AMPLITUDE OF THE SAID PULSED OSCILLATOR SIGNALS; MEANS FRO RECEIVING A PORTION OF THE SAID TRANSMITTED ULTRASONIC SIGNALS AFTER TRANSMISSION THROUGH A SECTION OF THE SEDIMENTATION VESSEL; MEANS FOR AMPLIFYING THE SAID RECEIVED SIGNALS; MEANS FRO DERIVING A SECOND D.C. VOLTAGE, THE VALUE OF WHICH IS PROPORTIONAL TO THE AVERAGE AMPIITUDE OF THE SAID AMPLIFIED RECEIVED SIGNALS; MEANS FOR DERIVING A THIRD D.C. VOLTAGE THE VALUE OF WHICH IS PROPORTIONAL TO THE DIFFERENCE BETWEEN SAID FIRST AND SECOND D.C. VOLTAGES; AND MEANS FOR RECORDING SAID DIFFERENTAIL VOLTAGE AS A FUNCTION OF TIME AS THE SEDIMENTATION PROGRESSES.