JIS R 3106:2019 specifies methods of determining the transmittance/reflectance of visible light and the transmittance/reflectance/absorptance of solar radiation as well as the emissivity of thermal radiation at ambient temperature for glazing 1), using a spectrophotometer. Also, this Standard specifies the method to calculate the total solar energy transmittance when glazing is used as building apertures. These characteristic data can serve as a basis for light, heating/cooling and ventilation calculations of rooms and can permit comparison between different types of glazing.