Sound Power Level Measurements - Earthmoving Machinery (Dozer@ Loader@ Excavator@ and Backhoe) - In Place Dynamic - Sound Pressure Level or Sound Intensity Method
The requirements for setting up and operating the machinery@ the microphone array and hemispherical measurement surface are given in this document. This document shall be used in conjunction with manufacturer's recommendations pending finalization of ANSI documents on the subject of sound intensity procedures. The accompanying sound intensity procedure clarification is provided pending more widespread understanding of sound intensity Purpose: This draft procedure is to be used to determine the exterior A-weighted equivalent sound power level of static and in-place dynamic machines (dozer@ loader@ excavator@ backhoe) similar to the sound power obtained of unloaded moving machines described in ISO 6393 (static) and ISO/DIS 6395 (dynamic) sound power test procedures. Test instrumentation recommended includes conventional integrating sound pressure level methods or the two (paired) microphones sound intensity method (which permits measurement in the factory environment). This methodology provides a practical indoor alternative to the ISO procedures better suited to high volume conformance testing for machines powered by piston type internal combustion engines. This procedure assumes that the dominate sources are not highly sensitive to load (cooling fan@ engine and track system). This test can be used as a substitute for the ISO 6393 (static) and ISO/DIS 6395 (dynamic) sound power tests for many machine types and at least a more repeatable measure for the remainder. The SAE J1372 JUN83@ Sound Power Determination - Earthmoving Machinery - Static Condition test remains valid for only a static test@ but it is not necessary to run SAE J1372 in addition to SAE J1805