FIELD: metrology.
SUBSTANCE: invention relates to the metrology in industrial acoustics. Objects in the reverberation chamber acoustic characteristics studying method is in that on the reverberation chamber floor a noise source is placed and measuring the sound power level by means of microphones arranged along the measuring surface outline. Power level is calculated by the formula Lp=Lcp+10lg(A/A0)-6, where Lcp is the average sound pressure level in the chamber; A is the chamber equivalent sound absorption area. Investigated sound-absorbing element is made in the form of rigid and perforated walls, between which multilayer sound absorbing element is arranged, which is made in the form of two layers: one, adjacent to the rigid wall, is the sound-absorbing, and the other, adjacent to the perforated wall, is made with perforation from the complex shaped sound-reflecting material, consisting of uniformly distributed hollow tetrahedrons. As the sound-reflecting material, the aluminum-containing alloys based material is applied, with their subsequent filling with titanium hydride or air with density within 0.5…0.9 kg/m3 with the following strength properties: compressive strength within 5…10 MPa, bending strength within 10…20 MPa, for example foamed aluminum, or the “Shumostop” type glass staple fiber based soundproofing plates with the material density equal to 60÷80 kg/m3, or the magnesia binder based material with reinforcing fiberglass cloth or glass-fiber mat.
EFFECT: increase in the accuracy of the noise attenuation efficiency measuring of the new sound-absorbing elements under investigation acoustic characteristics.
1 cl, 3 dwg
