GB/T 20148-2006 (English Version) PDF

Standard No.: GB/T 20148-2006
Language: Chinese, Available in English version
Release Date: 2006
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 20148-2006

Scope: This standard specifies a set of outdoor daylight conditions that are theoretically and practically related to sunlight and ceiling lighting. The given luminance distributions have the following characteristics: 1) They are all symmetrical about the solar meridian and are a function of the angular distance Z_S between the sun and the zenith. 2) They are defined as smooth continuous functions. This distribution of brightness is typical of a clear sky, characterized by clouds that are monochromatic. They provide an approximation of a patchy cloudy sky that is accurate enough for many practical daylight calculations. 3) The relative brightness of any point in the sky depends on the angle x between the bin of the sky and the sun and the angle Z between the bin of the sky and the zenith. This relative brightness is given by two functions: the relative scattering characteristic curve f(x) and the brightness hue Φ(Z) between the viewing distance and the zenith.

GB/T 20148-2006 Referenced Document

GB/T 2900.65 Electrician Terminology Lighting*， 2023-11-27 Update
ISO 31-6:1992 Quantities and units; part 6: light and related electromagnetic radiations