GB/T 2680-1994 in English

《GB/T 2680-1994建筑玻璃 可见光透射比、太阳光直接透射比、太阳能总透射比、紫外线透射比及有关窗玻璃参数的测定》由TC255（全国建筑用玻璃标准化技术委员会）归口，主管部门为中国建筑材料联合会
本标准规定了建筑玻璃可见光透射(反射)比、太阳光直接透射(反射、吸收)比、太阳能总透射比、紫外线透射(反射)比、半球辐射率和庶蔽系数的测定条件和计算公式。本标准适用于建筑玻璃以及它们的单层、多层窗玻璃构件光学性能的测定。

1 Subject Content and Applicable Scope

This standard specifies the determination conditions and calculation formulae of light transmittance (reflectance), solar direct transmittance (reflectance and absorptance), total solar energy transmittance and ultraviolet transmittance (reflectance), hemispherical emissivity and shading coefficient for glass in building.

This standard is applicable to the determination of optical performance for the glass in building and its single and multiple glazing units.

2 Determination Conditions

2.1 Sample

2.1.1 The samples of general glass in building and single glazing units shall be the glass slices of the same material.

2.1.2 The samples of multiple glazing units shall be the combination of single glass slices of the same material.

2.2 Standard sample

2.2.1 In the determination of spectral transmittance, an air layer of the same thickness as the sample shall be used as a reference standard.

2.2.2 In the determination of spectral reflectance, the reference whiteboard configured with instrument shall be used as the reference standard.

2.2.3 In the determination of spectral reflectance, the standard specular reflector shall be used as the working standard, such as an aluminized mirror, instead of a perfect reflecting diffuser.

2.3 Instrument

2.3.1 Spectrophotometer, equipped with a specular reflection unit in determination of spectral reflectance.

2.3.2 Wavelength range

1 Subject Content and Applicable Scope
2 Determination Conditions
3 Determination of Parameters
4 Determination Report
Additional Explanations: