AS 1428.1-2009 PWD Code.pdf

AS 1428.1—2009                                           102



       B4 DETERMINATION OF LUMINANCE CONTRAST
       This Paragraph sets out a method for using the luminous reflectance values to
       calculate the required minimum luminance contrast between two adjacent or
       contiguous surfaces when the luminous reflectance of the products are known, and
       is based on the following equation:
              C = 125 (Y 2 − Y 1)/(Y 1 + Y2 + 25) = 30
       where
              C = luminance contrast
              Y 1 = darker surface
              Y 2 = lighter surface
       The full set of limits is shown in Table B1.
       The luminous reflectance of the building elements has to lie above or below the
       lines illustrating the minimum and maximum luminous reflectance necessary, as
       shown in Figure B1.

                                                 TABLE B1
                         VALUES OF LUMINOUS REFLECTANCE REQUIRED
                         TO PROVIDE ADEQUATE LUMINANCE CONTRAST
                         AS A FUNCTION BETWEEN BUILDING ELEMENTS
                                              Minimum luminous    Maximum luminous
                            Luminous
                                               reflectance of a    reflectance of a
                        reflectance of the
                                               possible lighter    possible darker
                        building element
                                               building element    building element
                               95                        —               53
                               90                        —               50
                               85                        —               47
                               80                        —               44
                               75                        —               41
                               70                        —               38
                               65                        —               35
                               60                        —               31
                               55                        96              28
                               50                        90              25
                               45                        82              22
                               40                        74              19
                               35                        65              16
                               30                        57              13
                               25                        49              10
                               20                        41               7
                               15                        33               4
                               10                        25               1




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