Description: logarithmical measure of the pressure of a sound wave relative to a reference level; Name: acoustic pressure level
Description: Ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p, to the square of a reference value, p0, expressed in decibels; Name: Sound pressure level
Description: the norm the material. The material number is taken from this norm. Type and number of the norm with issue year and issue month must be given; Name: Reference norm material of the displacement units