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This SAE Recommended Practice establishes the test procedures, environment, and instrumentation for determining the maximum exterior sound level of passenger cars, multipurpose vehicles, and light trucks having a gross vehicle mass (weight) rating of 4540 kg (10 000 lb) or less. This document is intended for use when the maximum sound generating capability of any applicable vehicle is to be measured. The test procedure is characterized by having fixed terminal conditions (attainment of rated engine speed at a fixed end point on the test site) in contrast to the procedure of SAE J986 NOV81, Sound Level for Passenger Cars and Light Trucks, which has fixed initial conditions (specified initial vehicle speed at a fixed acceleration point on the test site). Full-throttle acceleration and closed-throttle deceleration of the vehicle are included in both procedures.

The scope of the recommended practice includes the system performance requirements for the entire sound measurement system. It provides the methods needed to verify Type 1 or Type 2 instruments. However, it also provides a method to qualify an SDAS that does not meet the requirements in their entirety, but can be used provided knowledge of the test data is obtained and an iterative process is followed in qualifying the SDAS. The system need only be qualified for the dynamic characteristic and weighting mode in which it is to be used. The scope of this document does not include qualification of system components for harmonic distortion, tape recorder wow and flutter, etc. However, these factors must be considered when determining system performance, especially where spectral information is sought. The references in Section 8 should be consulted for general performance requirements and precautions regarding instrumentation for acoustical measurements.