(at a surface)
The complex quotient of the sound pressure and the volume velocity through the surface.
Note: This definition is valid only for sinusoidal vibrations in the steady state.
Reference: I.E.C. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM