FIELD: chemistry.
SUBSTANCE: method involves mounting an ultrasonic transducer near one end of a thin plate in air; the transducer is made and excited such that a normal wave propagates in the plate, said normal wave being sensitive to longitudinal impedance of a liquid, for example, a zero-order symmetrical Lamb wave; receiving an echo signal reflected from the opposite end of the plate; measuring the amplitude thereof; beginning to immerse the plate in a measuring vessel into which the monitored suspension is fed; before feeding to the monitored article made of ferromagnetic materials, the plate is moved in a direction perpendicular the emulsion surface, wherein movement of the plate in both the air and the emulsion itself is carried out with constant velocity V; continuing to measure the amplitude of the echo signal reflected from the opposite end of the plate; with selected periodicity, recording the time of beginning to immerse the plate into the liquid, for example, when the amplitude of the echo signal decreases; storing the numerical value of the amplitude and the time corresponding to said reduction; measuring the time interval; measuring and storing numerical values of the amplitude of each n-th echo signal during immersion; at a time T=L/V (L is a predetermined immersion depth), movement of the plate is stopped; calculating the damping coefficient of the echo signals per unit length and the average damping coefficient value, then determining concentration of the investigated suspension from the calculated average value and calibration carried out in advance on suspension with known concentration of magnetic particles.
EFFECT: high reliability of monitoring concentration of magnetic suspensions.
2 cl, 2 dwg
