Luminance and radiance from the Malaysian sky / Marliana Omar

In this study, the luminance and radiance of Shah Alam sky were measured using a sky scanner MS-321LR. The sky scanner was placed at a location with no obstructions. Therefore it was placed on top of a roof. The luminance and radiance were measured from 6.30am to 6.30pm for a week. The data were downloaded to a computer and analyzed using Excel Software.The illuminance and irradiance were then determined using a conversion factor. The ratio of illuminance to irradiance which is* luminous efficacy, K was then determined. The relationship between illuminance and irradiance was also obtained. The illuminance was found to be directly proportional to the irradiance. The average illuminance of Shah Alam sky for that respective week is 19978.67 lm/m2 while irradiance is 179.14 W/m2. The luminous efficacy, K for that respective week is 111.52 lm/W.