Rayl

Physical unit
Unit name	Rayl
Unit symbol	${\displaystyle \mathrm {Rayl} }$, ${\displaystyle \mathrm {rayl} }$
Physical quantity (s)	Acoustic impedance
Formula symbol	${\displaystyle Z_{\mathrm {F} }}$
dimension	${\displaystyle {\mathsf {M\;L^{2}\;T^{-1}}}}$
system	CGS system of units
In SI units	${\displaystyle \mathrm {1\,MKS~Rayl=1\;{\frac {N\,s}{m^{3}}}} }$
In CGS units	${\displaystyle \mathrm {1\,CGS~Rayl=1\;{\frac {g}{cm^{2}\,s}}} }$
Named after	Lord Rayleigh
Derived from	Centimeter , gram , second

The Rayl (named after the English physicist John William Strutt, 3rd Baron Rayleigh ) is an outdated and illegal unit of the specific acoustic impedance . There are two different definitions that differ by an order of magnitude:

1. In the CGS system of units :

   ${\displaystyle 1\ \mathrm {CGS~Rayl} =10\ {\mathrm {kg} \over \mathrm {m^{2}\ s} }=1\ {\mathrm {g} \over \mathrm {cm^{2}\ s} }=10\ {\mathrm {Pa\ s} \over \mathrm {m} }}$

2. In the MKS unit system :

   ${\displaystyle 1\ \mathrm {MKS~Rayl} =1\ {\mathrm {kg} \over \mathrm {m^{2}\ s} }=0{,}1\ {\mathrm {g} \over \mathrm {cm^{2}\ s} }=1\ {\mathrm {Pa\ s} \over \mathrm {m} }}$

Individual evidence

1. ↑ Holger Pettersson, Gustav Konrad von Schulthess, David J. Allison: The Encyclopaedia of Medical Imaging: Physics, techniques and procedures / volume editors, Gustav K. von Schulthess, Hans-Jørgen Smith . Informa Health Care, 1998, ISBN 82-91942-01-3 .
2. ^ François Cardarelli: Encyclopaedia of scientific units, weights, and measures . Springer, 2003, ISBN 1-85233-682-X , pp. 555 ( limited preview in Google Book search).
3. ↑ Often referred to as the original definition.
4. ^ Z. Maekawa, Peter Lord: Environmental and architectural acoustics . Taylor & Francis, 1994, ISBN 0-419-15980-0 , pp. 366 .