Document ID: chunk:federal_register_of_legislation:F2024C00148:reg:12:p19
Version: federal_register_of_legislation:F2024C00148
Segment Type: reg
Provision Reference: reg 12 (pt 19/24)
Character Range: 281586–283999

near as possible to that of the test samples.
3.3. Non‑flat (convex) mirror measurement
 The measurement of the reflectance of non‑flat (convex) mirrors requires the use of instruments which incorporate an integrating sphere in the receiver unit (see figure 2).  If the instrument indicating meter indicates ne divisions with a reference standard mirror of E per cent reflectance, then, with a mirror of unknown reflectance, nx divisions will correspond to a reflectance of X per cent, given by the formula:

              Figure 1 Generalized reflectometer showing geometries for the two calibration methods

              Figure 2 Generalized reflectometer, incorporating an integrating sphere in the receptor.

Spectral tristimulus values for the CIE 1931 standard colorimetric observer[1/]
 (This table is taken from CIE Publication 50(45) (1970))
   λ                              x ( λ )                 ( λ )                  ( λ )      nm
 380 0.001 4 0.000 0 0.006 5
 390 0.004 2 0.000 1 0.020 1
 400 0.014 3 0.000 4 0.067 9
 410 0.043 5 0.001 2 0.207 4
 420 0.134 4 0.004 0 0.645 6
 430 0.283 9 0.011 6 1.385 6
 440 0.348 3 0.023 0 1.747 1
 450 0.336 2 0.038 0 1.772 1
 460 0.290 8 0.060 0 1.669 2
 470 0.195 4 0.091 0 1.287 6
 480 0.095 6 0.139 0 0.813 0
 490 0.032 0 0.208 0 0.465 2
 500 0.004 9 0.323 0 0.272 0
 510 0.009 3 0.503 0 0.158 2
 520 0.063 3 0.710 0 0.078 2
 530 0.165 5 0.862 0 0.042 2
 540 0.290 4 0.954 0 0.020 3
 550 0.433 4 0.995 0 0.008 7
 560 0.594 5 0.995 0 0.003 9
 570 0.762 1 0.952 0 0.002 1
 580 0.916 3 0.870 0 0.001 7
 590 1.026 3 0.757 0 0.001 1
 600 1.062 2 0.631 0 0.000 8
 610 1.002 6 0.503 0 0.000 3
 620 0.854 4 0.381 0 0.000 2
 630 0.642 4 0.265 0 0.000 0
 640 0.447 9 0.175 0 0.000 0
 650 0.233 5 0.107 0 0.000 0
 660 0.164 9 0.061 0 0.000 0
 670 0.087 4 0.032 0 0.000 0
 680 0.046 8 0.017 0 0.000 0
 690 0.022 7 0.008 2 0.000 0
 700 0.011 4 0.004 1 0.000 0
 710 0.005 8 0.002 1 0.000 0
 720 0.002 9 0.001 0 0.000 0
 730 0.001 4 0.000 5 0.000 0
 740 0.000 7 0.000 2 [2/] 0.000 0
 750 0.000 3 0.000 1 0.000 0
 760 0.000 2 0.000 1 0.000 0
 770 0.000 1 0.000 0 0.000 0
 780 0.000 0 0.000 0 0.000 0
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Explanatory figure

Example of device for measuring the reflection factor of spherical mirrors

C = Receiver
D = Diaphragm
E = Window of entry
F = Window of