| 摘要 |
PURPOSE:To take a measurement with a small sample and speedily without requiring any special reverberation chamber, etc., by connecting two acoustic pipes which have the same sectional shape to each other across the sample, and fitting a speaker to one end part and a sound absorber to the other end part. CONSTITUTION:The speaker 2 is fitted to an end part of one of acoustic pipes 1 and 1 which have the same sectional shape, and microphones 4 are inserted at >=2 specific positions. The sound absorber 3 is inserted into an end part of the other acoustic pipe and a microphone 4 is inserted at >=1 specific position. Those acoustic pipes 1 and 1 are connected together by connectors 5 which are arranged at the other-terminal sides of both acoustic pipes 1 along the outer peripheries of the pipes, have a small spring constant, and connect the acoustic pipes to both sides of the sample 6 without radiating a sound in the acoustic pipe to the outside. Then, signals of the microphones are processed on Fourier transform basis at the same time and data on them are processed by calculation. |
