Description: ten times the logarithm to the base 10 of the ratio of the sound power radiated by a sound source to the reference sound power (P0 = 10?12 W); Name: acoustic power level
Description: ten times the logarithm to the base 10 of the ratio of the sound power of a source, p, to a reference value, p0, expressed in decibels; Name: sound output level
Description: amount of the absolute value of the total head above the head, equivalent to the vapour pressure of the liquid at the particular temperature, with reference to the NPSH datum plane; Name: net positive suction head