INTERFEROMETER WITH NORMAL INCIDENCE OF SOUND WAVES FOR STUDYING ACOUSTIC CHARACTERISTICS OF SOUND-ABSORBING MATERIALS AND STRUCTURES Russian patent published in 2024 - IPC G01N29/00 

FIELD: measuring.

SUBSTANCE: invention can be used for investigation of acoustic characteristics of sound-absorbing materials and structures. Essence of the invention lies in the fact that the interferometer with normal incidence of sound waves for studying the acoustic characteristics of sound-absorbing materials and structures comprises an impedance pipe, microphones and a speaker attached to the pipe, holder for installation in impedance pipe of analysed sample, wherein impedance pipe consists of two coaxially installed pipes, for rigid connection of which a coupling is used, first pipe is rigidly fixed on the support plate by means of at least one support, and the second pipe is fixed with the help of at least one support on the linear movement module, which is part of the linear drive, wherein the linear displacement module, like the support of the first pipe, is mounted on the support plate; on the end face of the first pipe, on the side opposite to the end face with the coupling, a speaker is installed; at least one microphone is installed on the first pipe, flush with the inner channel of the pipe; inner channel of the second pipe is a cage for installation in it of the analysed sample, which is installed from the end of the second pipe facing the coupling; inside the cage there is a movable piston with a rod, at the end of the second pipe, on the opposite side relative to the end facing the connecting coupling, a cover with a hole for the rod outlet is fixed; linear drive is connected to control unit.

EFFECT: improved operational manufacturability of the device, reduced time for installation and removal of the analysed samples, reduced spread of the obtained acoustic characteristics for the analysed samples.

2 cl, 1 dwg