Description: Integral of the product of the sound pressure p and the component of the particle velocity un, which is perpendicular to a surface at a point of this surface, over this surface; Name: Acoustic power
Description: determined through a surface, product of the sound pressure, p, and the component of the particle velocity, un, at a point on the surface in the direction normal to the surface, integrated over that surface; Name: sound power
Description: PN (nominal pressure) is an alphanumeric variable for reference purposes, relating to a combination of mechanical and measurement properties of a pipe component. It comprises the letters PN followed by a dimensionless number (according to EN 1333/96.08); Name: Nominal pressure of the muffs, A1