METHOD FOR DETERMINING SPEED AND TYPE OF CORROSION Russian patent published in 2021 - IPC G01N17/02 

FIELD: corrosion rate determination.

SUBSTANCE: invention relates to methods for determining the rate of corrosion in automated corrosion monitoring systems. The method for determining the rate and type of corrosion consists in the fact that a combined piezoelectric transducer, an acoustic emitter and an acoustic receiver are placed on the inner surface of a witness sample made in the form of a metal plate with external and internal opposite parallel surfaces, the external surface of the witness sample is placed in the medium causing it to corrode, and the inner surface of the witness sample is closed with a protective casing preventing contact with the medium, a normal sensing signal is supplied to the input/output of the combined piezoelectric transducer in the form of an electric pulse, which excites a pulse of ultrasonic longitudinal acoustic wave of the normal sensing sounding signal in the witness sample, and the value of the current thickness of the witness specimen during normal probing, an emitting signal of oblique sounding is supplied to the input of the acoustic emitter in the form of an electric pulse, according to the difference in time moments when the emitting signal of oblique sounding is fed to the input of the acoustic emitter and the reflected bottom signal of oblique sounding is fixed at the output of the acoustic receiver, the value of the current thickness of the witness sample for oblique sounding is determined, on based on the comparison of the values ​​of the current thickness of the witness specimen, determined for normal sounding, and the thickness of the witness specimen for normal sounding, the rate of corrosion occurring on the outer surface of the metal plate of the witness specimen is calculated, based on the comparison of the value of the current thickness of the witness specimen for normal sounding and the current thickness of the witness specimen for oblique sounding, the type of corrosion taking place on the outer surface of the metal plate of the witness sample, in this case, the location on the inner surface of the witness sample of the combined piezoelectric transducer, the material of the emitting and receiving prisms, the angles of the inclined faces and their location on the inner surface of the witness sample are chosen such that the scattering region coincides with the probing region on the outer surface of the witness sample, in this case, the acoustic emitter can excite a probing signal in the witness sample, and the acoustic receiver can receive a bottom signal from the witness sample material both in the form of pulses of ultrasonic transverse and longitudinal acoustic waves.

EFFECT: reducing the load on the cathodic protection device and increasing the accuracy of assessing the rate and type of corrosion.

1 cl, 1 dwg