METHOD FOR MEASURING SOUND VELOCITY IN THIN POLYMERIC SOUND-TRANSPARENT FILMS Russian patent published in 2022 - IPC G01N29/00 

FIELD: measuring technology.

SUBSTANCE: invention is intended for measuring the longitudinal speed of sound in thin polymeric sound-transparent films. The substance of the invention lies in the fact that the coefficients of ultrasound transmission through the film and reflection from it are measured, while the calculated values of these coefficients are compared with their measured values, and the calculations of the transmission and reflection coefficients are performed at given frequencies and sound speeds and at one selected value thickness of the film, to determine the minimum difference between the calculated and measured transmission coefficients, their graphical dependences are plotted on the estimated sound speed in the film for each given frequency, the desired sound propagation speed in the film is determined by the minimum difference between the measured and calculated values of the ultrasound transmission coefficients through the film and reflection from it in a given frequency range.

EFFECT: providing the possibility of measuring the speed of sound in PET films (in polyethylene terephthalate films) of ultra-thin thickness.

11 cl, 4 dwg