AS 1428.1-2009 PWD Code.pdf

                                                     103                                      AS 1428.1—2009




      NOTE: Luminous reflectance of building elements must lie outside the shaded area. Of the
      2 elements the lighter element is to be above the shaded area and the darker element is to be below
      the shaded area.


                       FIGURE B1 LIMITING VALUES OF LUMINOUS REFLECTANCE
                                      OF BUILDING ELEMENTS


      B5 MEASUREMENT OF LUMINANCE CONTRAST—ON-SITE
      B5.1 General
      This Paragraph sets out the method for on-site measurement of contrast of building
      elements. This method is carried out under the prevailing lighting condition(s) and is
      also applicable where a building element is not uniformly coloured.
         NOTE: The method specifies a luminance meter (photometer) with a 1° measurement
         field. Such meters are widely available. While a wider field of view such as 3° may be
         preferable because it permits a shorter measurement distance, luminance meters with
         wider fields are less common and substantially more expensive.
      B5.2 Instrumentation
      A single lens reflex luminance meter commonly known as a photometer with a 1°
      measurement field and a spectral responsivity approximating the CIE 1931
      Standard Observer V (λ) function as specified in ISO 11664-1 are to be used.
      B5.3 Procedure
      The procedure is as follows:
      (a)    Mount the luminance meter on a tripod so that the centre of the objective lens
             is at a height of 1.6 ±0.1 m (representative of the eye height of a standing
             person).
      (b)    Locate the tripod so that measurements can be made of both building
             elements without moving the tripod. Direct the luminance meter to the point
             where the width of the smaller building element just fills the measurement
             field. Choose an area that is visually uniformly lit. Record the luminance L 1.
      (c)    Direct the luminance meter to measure the second building element
             immediately adjacent to the previous location of the first building. Record the
             luminance L 2.

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