Usage of infra-red waves in household appliances, television controllers and intruder alarms
- Infra-red radiation is emitted or absorbed by every object. We feel warm under the sun as we absorb more IR radiation than we emit (gain internal energy). We feel cool in an air-conditioned room as we emit more IR radiation than we absorb (lose internal energy).
- IR radiation is commonly used in wireless remote control units for air-conditioners, television, sound systems and similar devices. The remote unit emits coded IR that is detected by the appliances.
- IR radiation can be detected using electronic sensors, as in an intruder alarm system. Modern IR detectors are solid state detectors which act rather like TV cameras, but in the IR range.
Interesting tip: Your smartphones’ camera is able to detect infra-red. You can check this out by pointing a wireless remote control at the camera. The infra-red radiation will register as a red light.