Daylight measurement in models: New type of equipment

Standard laboratory methods for predicting daylight illumination in buildings involve model testing in large artificial skies. Usually only one sky luminance distribution can be simulated. In the equipment described in this Note, the sky is divided into a large number of zones, and the daylight coefficients are measured. The illuminance beneath any sky luminance distribution can then be found by multiplying the coefficients by the appropriate sky luminance values. The equipment serves also as a computer-controlled heliodon which permits measurement of building illuminance under direct sunlight.