Document ID: chunk:federal_register_of_legislation:F2023C00161:reg:400:p5
Version: federal_register_of_legislation:F2023C00161
Segment Type: reg
Provision Reference: reg 400 (pt 5/10)
Character Range: 37098–40023

determine whether the electrodes are correctly positioned relative to the reference axis and the reference plane.

       Measuring direction A and B as defined on sheet D1R/D2R/1

Dimension in mm  Production light sources  Standard light sources
a1               d + 0.5                   d + 0.2
a2               d + 0.7                   d + 0.35
b1               0.4                       0.15
b2               0.8                       0.3
c                4.2                       4.2

d = diameter of the electrode < 0.3

The top of the electrode nearest to the reference plane shall be positioned in the area defined by a1 and b1.  The top of the electrode furthest from the reference plane shall be positioned in the area defined by a2 and b2.
Categories D1R and D2R  Sheet D1R/D2R/5

Position and form of the arc

This test is used to determine the form and sharpness of the arc and its position relative to the reference axis and plane by measuring its bending and diffusion in the central cross section D and by measuring stray light intensities in zone A and at lines B and C.

When measuring the relative luminance distribution in the central cross section D as indicated in the drawing above, the maximum value Lmax has the distance r from the reference axis.  The points of 20% of Lmax have the distance s, as shown in the drawing below.

Dimension in mm  Production light sources  Standard light sources
r                0.50 +/- 0.25             0.50 +/- 0.20
s                1.10 +/- 0.25             1.10 +/- 0.25

When measuring the luminances from measuring direction B as defined on sheet D1R/D2R/6 with a set-up as outlined in Annex 5, however with a circular field of 0.2Mmm diameter, the relative luminance expressed as a percentage of Lmax (at cross section D) shall be:

Zone A <4.5 %

Line B <15 %

Line C <5.0 %

The area of zone A is defined by the black coating, the outer bulb and a plane at 24.5mm from the reference plane.

Categories D1R and D2R  Sheet D1R/D2R/6

       Position of the black stripes

This test is used to determine whether the black stripes are correctly positioned relative to the reference axis and the reference plane.

When measuring the luminance distribution of the arc in the central cross section as defined on sheet D1R/ D2R/5, after having turned the light source so that the black stripe is covering the arc, the measured luminance shall be < 0.5% of Lmax.

In the area defined by alpha1 and alpha3 the black coating may be replaced by any other means which prevents light transmission through the specified area.

Dimensions                              Production light sources  Standard light sources
alpha1                                  45 degrees +/- 5 degrees
alpha3                                  70 degrees min
alpha4                                  65 degrees min
beta1/24, beta1/30, beta2/24, beta2/30  25 degrees +/- 5 degrees