00:41 Feb-11-2004 Neil Burleigh Sales Krautkramer Australia Pty Ltd, Australia, Joined Dec 2002 146
Re: Acoustic Impedance ----------- Start Original Message ----------- : Hi, : I am a student from India. Currently doing a project on ultrasonics for paper. Can anyone tell me the acoustic impedance of paper. : Thanks in advance. ------------ End Original Message ------------
Hello Sarath,The acoustic impedance Z can be defined as the product of the density and velocity of sound of a given material. Wood for example is elastically anisotropic - the velocity of sound is different across the grain compared with along the grain. Paper is generally made from wood fibers so the velocity of sound will vary according to the direction of the fibers. Plus the velocity of sound in wood will vary with the type, from 500m/s (cork) up to nearly 5000m/s (Douglas fir). All this means that the a simple answer for "What is the acoustic impedance of paper?" is not easily supplied. More information needs to be known.