This SAE Recommended Practice provides laboratory test procedures, requirements and guidelines for electronic siren systems with a single loudspeaker, and electromechanical sirens for use on authorized emergency vehicles, which call for the right-of-way. This document is applicable only to such sirens that have all dimensions across the sound-emitting opening equal to or less than 0.5 m. Test procedures and performance requirements for individual system components are not included in this version. Data obtained from measurements of siren performance depend not only on the characteristics of the siren tested, but additionally on the test procedures and the characteristics of the measurement instrumentation and test environment. These additional factors must be well defined and controlled to obtain reliable data. Detailed test methods are described here, which include specifications for a laboratory environment, to minimize the measurement uncertainty and obtain accurate and reproducible measurement results. Such results are necessary to qualify the performance of all sirens as equally as practicable. Requirements have been established based on the laboratory-measured performance of sirens that have been effective in emergency service.
SAE J1849 will be stabilized at this time because no further changes to the procedures or requirements are foreseen in the immediate future since the April 2008 updates were made. If proposed changes come about the document will be opened for review and action.