It is the form of radiation used for making non-contact temperature measurements. The resistance measured between two insulated points on a transducer when a specific dc voltage is applied at room temperature. A process or area that is a constant temperature. The basic unit of thermal energy. Several types of physical heat transfer mechanisms can be modeled as linear conductors, including conduction, convection, and mass flow.
Louvers are active thermal control devices used on spacecraft.
As the temperature of the radiator gets hotter, the mask is withdrawn, exposing the radiator. The drive mechanism is usually a bi-metallic actuator, but active control could be used. There are several styles of louvers. A bladed version is shown below. Mass flow conductors are actually a special type of linear conductor.