ACOUSTIC INTERFERENCE METER Russian patent published in 1996 - IPC

FIELD: measuring. SUBSTANCE: one end of metal tube 1 has casing 2 with piston 3. Another end of same tube has box 4 with loudspeaker 5 and mike 6, which is attached to electric-driven trolley 7 running along guides 8. Metal rod 9 runs through hole in leg limb of loudspeaker 5 and is connected to mike 6 through adapter 10. Mike 6 is connected to automatic control unit, which has input unit, indication unit 17, OR gate 18, correction unit 19, distance unit 20, control unit 21, sound- frequency oscillator 22, two final switches 23 and 24, driving mechanism 25, distance transducer 26. Input unit has maximal and minimal value detection registers 13 and 15 and two comparison circuits 14 and 16. Sample 27 for investigation is loaded to casing 2. Device provides possibility of automation of measuring energy and frequency characteristics of materials. EFFECT: increased precision of sound absorption and impedance indices, increased speed of measurements. 2 cl, 2 dwg