... flatness in physical is not the necessary condition direction for testing accuracy .Specifications: Characteristics:High quality integrating spheres for ... ,or appliances from AC 100 to 277V within 300W.2. Testing parameters: Color temperature (CCT), Lumen, Luminous, efficiency. Voltage, ... . The input voltage is the same as the testing voltage.Testing timeonly about 10 seconds.Testing errorwithin 3~5%