This document provides design guidelines, test procedure references, and performance requirements for omnidirectional and selective coverage optical warning devices used on authorized emergency, maintenance and service vehicles. It is intended to apply to, but is not limited to, surface land vehicles.
The definition of LIGHT SOURCE was renamed to EWD LAMP ASSEMBLY.
Test voltages were added to accommodate the electrical system voltages of industrial vehicles.
The flash rate limits were revised from “at least 1 Hz and not more than 4 Hz” to “at least 1.0 Hz and not more than 4.0 Hz” to eliminate rounding errors.
References to SAE J2139 were added as an alternative to SAE J575 to accommodate devices intended for vehicles wider than 2032mm.
A provision was added to allow the use of the wideband random vibration test defined in SAE J575 in place of the vibration test procedure specified in SAE J2139 for large devices, such as light bars, since these devices are too large to be accommodated on the vibration machine specified in SAE J2139.
A requirement was added that test samples which exhibit a partial outage of non-filament EWD lamp assemblies must still comply with the photometric requirements upon the completion of any of the required tests.
The photometric test procedure was revised to ensure that sources whose output increases prior to stabilizing will still comply with the photometric requirements at their lowest output levels.
The photometric test procedure was revised to clarify how optical warning devices containing multiple EWD lamp assemblies should be evaluated.
The optical warning device class definitions were revised to differentiate between omnidirectional and selective coverage devices.
The definition of pseudo-random flash pattern was added.
Requirements for pseudo-random flash patterns were added to section "FLASH RATE AND FLASH PATTERNS".
Sections 5.7 and 6.7 were renamed "FLASH RATE AND FLASH PATTERNS".
The "Optical Warning Devices Containing Multiple Light Sources" and "Flash Pattern Compliance" guidelines were moved from the Installation Guidelines section to the appropriate locations in Section 5, "Tests".