ASA S1.8 PDF download

ASA S1.8 – American National Standard for Reference Values for Levels Used in Acoustics and Vibrations

This standard provides certain reference values to be used for acoustical and vibratory levels. Levels,when used in this standard, refer to a descriptor of mathematical calculation in which a ratio is used. Thereference value is the denominator of that ratio. Reference values are stated in the International Systemof Units (SI). The descriptor of most acoustical levels is the decibel, abbreviated “dB”. Levels are equal toten times the common (base-10) logarithm (abbreviated lg) of an appropriate nondimensional ratio of avariable quantity (in the numerator) to a reference value of the same kind (in the denominator). Themultiplier ten is used when the numerator is a power or power-like quantity (such as the time average ofthe square of a time-varying sound pressure or vibration acceleration) or an energy-like quantity (such assound exposure).