Replaced Table 1 with Figure 1 and Table 2 with Figure 2 as requested by Lighting Advisory Group. Changed all related references to Table 1 and Table 2.
Figure 1 and Figure 2 photometric values revised to a reference luminous flux of a light source at 13.2 V rather than the traditional 12.8 V.
The original SAE photometric table based on a reference luminous flux for a design voltage of 12.8 V was developed to harmonize with ECE R19, whose photometric table was based on a reference luminous flux for a design voltage of 12.0 V. The SAE table was converted from the 12.0 V ECE Conformity of Production (COP) intensity values to 12.8 V using a multiplication factor to compensate for the voltage difference. However, constant current light sources like the ones used for LEDs and HID were not fully considered during this development. A constant current light source lamp will output the same intensity at any given test point at 12.0 V and 12.8 V. A filament light source over the same two voltages would output approximately a 20% difference in intensity using the equation:
This results in a greater restriction in terms of harmonization for constant current light source front fog lamps.
ECE R19 originally resolved this issue by including a 1.43 multiplication factor (1.0/0.7) for HID light sources. This factor was not included in the SAE document. To resolve this issue, ECE R19 moved from a 12.0 V photometric table to 13.2 V photometric table and removed the 0.7 multiplication factor for constant current light sources. Reference ECE-TRANSWP29-GRE-62-01e. Moving to a reference luminous flux representative of 13.2 V also aligns with the agreement that ECE and SAE would migrate to a common design voltage of 13.2 V. To harmonize with ECE R19 and to resolve the constant current light source issue, it was decided to update the SAE photometric tables to be based on the reference luminous flux representative of 13.2 V.
To aid test labs with the transition to 13.2 V, a note was added to each figure which allows filament light source front fog lamps to be tested at the rated luminous flux representative of 12.8 V provided that the measured values at each test point is scaled by a factor of 1.10 based on the equation above. This eliminates the requirement for each test lamp to replace their 12.8 V accurate rated light sources with 13.2 V accurate rated light sources.
In Figure 2, replaced Zone 1 with 10 separate photometric test maximums to harmonize with ECE R19.
Included a note in 5.2.5 referencing the 13.2 V value.
Restricted the color of a front fog lamp used like a bending lamp or cornering lamp to white and lamps without this functionality from white to selective yellow to harmonize with ECE.
With these changes, SAE J583 and ECE R19 are harmonized for photometry requirements for an “F3” front fog lamp.