rayl

(acoustics) A unit of specific acoustical impedance, equal to a sound pressure of 1 dyne per square centimeter divided by a sound particle velocity of 1 centimeter per second. Also known as specific acoustical ohm (Ω_s); unit-area acoustical ohm.

[Etymology: J. W. Strut, 3rd Lord Rayleigh; UK 1842-1919] acoustics (Metric) A unit of specific impedance, the ratio of the effective sound pressure to the effective particle velocity at the surface, identically the product of volumic mass of a gas and the speed of sound therein. The rayl has the dimension of force·second per volume, and is defined coherently, but thereby of different size, in both c.g.s. and m.k.s.

Metric-c.g.s. dyn·s·cm^-3(= cm^-2·g·s^-1 in m.g.s. base terms) = 10 N·s·m^-3.

Metric-m.k.s. N·s·m^-3(= m^-2·kg·s^-1 in m.k.s. base terms).

For air, the specific impedance is around 400 rayl_m.k.s..