Edwards Light Output White Paper

EDWARDS ADAPTABEACONS light output light source discussion Effective Light Output VELO signaling depends on both perception and understanding of the signal being transmitted In the case of audible it is important to select a tone e g bell horn siren that not only conveys meaning but is also distinguishable from or background sounds Loudness is also an important factor enough to be perceived over ambient dB but not much that either distortion or listener damage occur same type of factors affect visible signal selection Ambient or background light may affect the choice of light e g steady flashing rotating or strobe while message type may dictate color choice e g red for stop or perception specifically the ability of the viewer to effectively see and comprehend the visual signal is perhaps the important feature of any visual signal AdaptaBeacons have thus been designed to maximize viewer perceptibility This focus on Viewer Effective Output VELO is most noticeable in the Edwards lens design The unique double fresnel lens results in four characteristics that significantly enhance viewer perception The refractive feature of the inner fresnels causes the lens to fill resulting in a rectangular column of light This the time of illumination thus significantly enhancing retinal retention Light sources are positioned in the focal point of the lens thus enabling the lens magnifying ring to effectively project visual signal the beacon The refractive external fresnels function also to diffuse the light This enhances visibility for viewers located adjacent By ensuring that the lens is filled with light any spots are eliminated This is particularly important to viewer when strobe light sources are involved While hotspots generate high light output numbers they generally in decreased viewer perception as viewers squint or turn away in order to avoid the flash Additionally the tends to wash out lens color resulting in a flash thus minimizing the color coded message Output Data manufacturers light output information Edwards included needs to be evaluated against many criteria including at which light is to be viewed lens color amount of lens pigmentation viewer perceptibility and in the case of VELO there are no standardized agency testing criteria for measuring light output of general non fire alarm visual For this reason Edwards has opted to specify strobe tube output in joules resultant effective candela and peak ratings See Table 1 for Edwards Strobe Light Output Data tube manufacturers all supply tube life data Edwards has opted when using this information to report effective life to only a 25 decrease in light output Obviously the greater the decrease the longer will be the stated tube See Table 1 for Edwards Strobe Tube Life Data Tube Life Data ADAPTABEACONS 1 Edwards Strobe Tube Light Output and Life Life Tube No Replaceable Replaceable No Series Series Series Series Series Series Series Series Series S1 Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Replaceable Replaceable Replaceable Replaceable at operating power to 75 efficiency known as candela seconds Refer to Technical Reference Appendix for calculation base ADAPTABEACONS Incandescent and Halogen Bulb Light Output halogen bulbs the manufacturer lumen rating is specified This measures effective light output in all directions Table 2 for bulb light output ratings and Incandescent Bulb Life source life is also an area of some confusion as there are no current industry standards for measurement At the time ambient conditions e g voltage vibration and duty cycles can significantly effect bulb life Improper can also dramatically decrease both bulb and tube life reporting bulb life Edwards is using manufacturer supplied data which assumes a 100 constant duty cycle and interpolating the effects of the average flash rate again assuming a constant duty cycle See Table 2 for bulb Life ADAPTABEACONS 2 Edwards Incandescent and Halogen Bulb Light Output and Life Life Life No No Trade 94 Industry Trade 1692 Industry Trade 1692 Rating Halogen Halogen Industry Trade 25T8DC Halogen Trade 94 Industry Trade 1692 Industry Trade 1692 Halogen Halogen Industry Trade 25T8DC Halogen Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Series Industry Trade Industry Trade Trade 94 Trade 1638 Trade 1638 6 ea or 1ea Trade 1638 6 ea or 1ea Industry Trade 6 ea or 1ea 6 ea or 1ea 6 ea or 1ea Trade 1076 Trade 1638 Trade 1638 Trade 1638 Trade 1638 Halogen Halogen Halogen Halogen Halogen Halogen Series Series Trade 1638 Trade 1638 ADAPTABEACONS Life Life