Describes procedures for the measurement of sound pressure levels in the outdoor environment, considering the effects of the ground, of refraction due to wind and temperature gradients, and of turbulence. The measured sound pressure levels can be used to calculate sound pressure levels at other distances from the source or to extrapolate to other environmental conditions or to assess compliance with regulation. Describes two methods: 1: general method, outlines conditions for routine measurements; 2: precision method, describes strict conditions for more accurate measurements.
ANSI/ASA S12.18-1994 history
1994ANSI/ASA S12.18-1994 American National Standard Procedures for Outdoor Measurement of Sound Pressure Level