purposes. The heliodon is also used for curvature and annual reflectivity studies of “Leaf” at Arup in coordination with Betanit. Robotic Heliodon with Fixed Model This robotic heliodon is fully automated with a computer and has lights that go around the fixed scale model placed horizontally on the table. This kind of robotic heliodon is used separately or integrated with dome artificial sky for presentation, lighting design and research purposes. While in use with the artificial sky, the combined tool can replicate both the sun and the sky for great accuracy and obtain results of the daylight study. The fixed scale model can be bigger and heavier models than the other types which allow the source to go around the model for obtaining evaluation results, conducting presentations and observation. The robotic heliodon allows people to move easily around and inside it for daylighting studies. The automated robotic heliodon with a fixed model is used in research facilities, lighting companies and university laboratories such as: University of Kansas Lighting Research Lab, Lawrence, United States uses a heliodon sunlight simulator for daylight studies and research purposes. The device was developed by Dr Hongyi Cai and custom-made in China by Quanzhou HuaTian Measurement Equipment LLC. The simulation tool has the ability of 3D angular movements of the scale model of buildings around a fixed point of the model at a precision of 0.1o. The heliodon is installed in the darkroom for teaching purposes, research, and daylighting studies. HFT, Stuttgart University of Applied Sciences, Stuttgart uses a robotic heliodon at their Daylight Planning Lab. The lab uses two elements in their daylight simulator – an artificial sky and artificial sun. The artificial sun simulator consists of a halogen bulb with a parabolic reflector to replicate parallel sunlight. The heliodon integrated an artificial sky of 4.20m diameter with 30 fluorescent lamps. The control panel allows the replication of any solar orbit at any day and any global location. This integration facilitates the reproduction of the sky’s brightness and the circumsolar radiation in great accuracy. The architecture and design department uses the device for teaching purposes, daylight study, shadow study and research. Bartenbach, Tyrol – the lighting firm uses a heliodon (inside an artificial sky of 6.5m diameter) with many small lamps for daylighting design with visualization models and calculations. The lighting firm uses heliodon for daylight simulation in research and development for complex building structures.