The device to the exemplary embodiment of apparatus

摘要

The device includes a test pattern disc (1) which is mounted on a circular support (2). The disc is heated by a heating element (5) positioned behind the disc. The heating element is an electrical resistance with the temperature measured by a probe coupled to a regulation device which controls the supply of electricity to the resistance. The disc has a number of circular rings, with eight radiating spokes (21), made from a high emissivity material, and a number of low emissivity regions (22) formed between them.