AS 1428.1-2009 PWD Code.pdf

                                                      101                                      AS 1428.1—2009



      B3.3 Procedure
      The procedure is as follows:
      (a)    Calibrate the equipment in accordance with the manufacturer’s instructions.
      (b)    Locate the equipment on the surface to be measured.
      (c)    Take measurements in at least five locations (on each building element) or on
             five units of the product (such as samples, where five units are available).
             Where the surface does appear (visually) to be uniformly coloured, a minimum
             of 10 measurements have to be taken. Record the luminous reflectance
             (Y value) for each individual dry measurement that is taken. The luminous
             reflectance (Y value) of the CIE 1964 colour system is recognized in
             AS/NZS 1580.601.2.
      (d)    Unless wet measurements are deemed to be inappropriate, wet the surface of
             the product and ensure that the surface remains wet (such that water ponds
             on the surface) for a minimum of 5 min. Take measurements as in Step (c), as
             soon as possible after removing any unabsorbed water from the surface with a
             cloth or sponge that does not leave any solid residue. Record the luminous
             reflectance (Y value) for each individual wet measurement that is taken.
             Determine the mean dry luminous reflectance (Y d) and the mean wet luminous
             reflectance (Y w).
             NOTES:
             1   The use of standardized illumination conditions when making photometer
                 measurements could enable manufacturers to publish luminous reflectance values
                 that are consistent with those obtained using this Appendix.
             2   For standard colours, see AS 2700.
      The luminance contrast (C) of two surfaces has to be calculated using the following
      equation:
             C = 125 (Y 2 − Y 1)/(Y 1 + Y2 + 25) Bowman-Sapolinski equation*
      where
             C            = luminance contrast
             Y 1 and Y 2 = luminous reflectance values of the two surfaces
      B3.4 Report
      The following has to be reported:
      (a)    Full description of the surfaces tested with product details where known.
      (b)    The instrument geometry, the light source as being D65, the aperture and the
             observer angle.
      (c)    The locations of the measurements on the sample.
      (d)    The mean luminous reflectance of the building elements under the conditions
             set out in Paragraph B3.3.
      The corresponding data for other light sources and illuminant may also be reported.




      * An Improved Metric for Visual Differentiation using Colour-modified Clinical Eye Charts, Redeemer
      Baptist School North Parramatta Australia, Sapolinski,J., August 2009.

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