Sound level
(15) Sound level means the weighted sound pressure level measured by the use of a metering characteristic and weighing A, B, or C as specified in American National Standard Specification for Sound Level Meters S1.4-1971 or subsequent approved revision. The weighting employed must be specified, otherwise A-weighting is understood. (16) Sound pressure level means, in decibels, 20 times the logarithm to the base ten of the ratio of a sound pressure to the reference sound pressure of 20 micropascals (20 micronewtons per square meter). In the absence of any modifier, the level is understood to be that of a root-mean-square pressure. (17) Product means any construction equipment for which regulations have been promulgated under this part and includes test product. (18) Test product means any product that is required to be tested pursuant to this part.