SYSTEM FOR REAL TIME MEASUREMENT OF IMPEDANCE SPECTRA OR TRANSFER FUNCTIONS OF ACOUSTIC AND MECHANICAL SYSTEMS

摘要

A system (11) for real time measurement of a transfer function of an acoustic or mechanical system includes, a cylindrical tube (12), with a horn (13) concentrically located within the cylindrical tube (12) and having an axis of symmetry coincident with the axis of symmetry of the cylindrical tube (12). The end (17) of the horn (13) having the smallest cross-section is butted onto a cylindrical pipe (27), which is provided with a small orifice (14) at one end. The horn (13) expands exponentially to a larger orifice (15) at the other end. A transducer (18) drives into the large orifice and is driven by a signal synthesised by a synthesiser (90) via a power amplifier (21). Located near the small orifice (14) of the cylindrical pipe (27) is the second transducer (20), such that the sound level is emitted from the small orifice (14) and the response signals of the system, into which this sound level is injected, can be monitored. The second transducer (20) is connected to the response analyser (91) capable of receiving and analysing the signals from the second transducer (20).