DEVICE FOR EARLY DIAGNOSIS OF THE FORMATION AND DEVELOPMENT OF MICROCRACKS IN MACHINE PARTS AND STRUCTURES Russian patent published in 2023 - IPC G01N29/14 

FIELD: diagnostics of the occurrence and development of microcracks in machine parts and structures.

SUBSTANCE: character of the invention lies in the fact that the acoustic-emission converter is made in the form of an acoustic cell, the output of which is connected via a coaxial RF cable to the first input of an acoustic emission signal spectrum analyzer, made in the form of three infradine-type frequency mixers, with combined RF-band LC filters, providing the transfer of the spectrum of received acoustic emission signals from the regions of the low–frequency ultrasonic frequency range Δf_C into three high–frequency regions of the electromagnetic spectrum, with a band of intermediate frequencies: Δf_P1, Δf_P2, Δf_P3, without changing the parameters of the frequency spectrum of acoustic signals, the second input of the analyzer - the second inputs of the frequency mixers are connected to the output of a high-frequency generator - a heterodyne whose frequency is higher than the frequency spectrum of acoustic signals and is f _H, and the outputs of the frequency mixers are connected to three frequency-selective resonant narrowband RF signal amplifiers, with a frequency band: Δf_P1, Δf_P2, Δf_P3, respectively, for high frequencies Δf_C3, medium frequencies Δf_C2 and low frequencies Δf_C1 of primary acoustic signals received by an acoustic emission converter which correspond to the formation and growth of microcracks, the development of microcracks and, at the last stage, the formation of a through crack, respectively, and the outputs of resonant amplifiers are connected to three separate units for measuring the amplitude of single pulses, as well as to three separate blocks for the formation of rectangular pulses, the outputs of which are connected to the inputs of three separate digital pulse counters.

EFFECT: present invention enables to increase the noise immunity of the amplifying path, increase signal–to-noise ratio.

5 cl, 6 dwg