This SAE Recommended Practice sets forth the instrumentation and procedures to be used in measuring exterior sound levels of self-propelled agricultural field equipment of 15 kW (20 net engine hp) or greater. It is not intended to cover operation of safety devices (such as alarms), or equipment used primarily in stationary operation. The sound levels obtained by using this test procedure are repeatable and representative of the higher range of sound levels generated by the machine in normal road transport. The sound levels are not intended to represent the average or equivalent sound levels over a field use cycle.