If the DUT generates very little heat, then the ambient temperature and the DUT temperature would be very similar. For this type of test the Thermal Chamber would be a good choice. However, for devices that dissipate power the temperature gradient between ambient and the surface temperature of the device can be very large. For this type of application the TEC and TEC controller are ideal. By making direct contact to the device the temperature can be maintained at the TEC and the DUT surface. Thermal Chambers also have gradient temperatures within the chamber from side to side and top to bottom which can cause erroneous temperature at various points on the DUT. The TEC is referred to as Case temperature control and the Thermal Chamber is referred to as Ambient temperature control. Devices such as ICs, LED modules, laser diodes, solar cells, DC/DC or AC/DC power modules are best suited for TEC controller and TEC platform thermal testing.