Lämpödetektorit

Lämpödetektorit, or thermal detectors, are devices that sense thermal radiation, typically in the infrared spectrum, and convert it into an electrical signal. This allows them to detect the presence and intensity of heat emitted by objects. They are crucial components in a wide range of applications, from night vision goggles and thermal imaging cameras to remote temperature sensing and early fire detection systems.

The working principle of most thermal detectors relies on the heating effect of absorbed infrared radiation. When radiation strikes the detector material, it causes a temperature rise. This change in temperature is then measured by a transducer element. Different types of transducers are employed, including thermistors, which change their electrical resistance with temperature, and pyroelectric materials, which generate a voltage when their temperature changes. Bolometers, another common type, measure the change in resistance of a material heated by absorbed radiation. Uncooled microbolometers have become particularly widespread due to their relatively low cost and ease of integration.

The sensitivity and response time of a thermal detector are key performance parameters. Sensitivity determines how small a temperature change the detector can register, while response time indicates how quickly it can react to a change in thermal input. These detectors are often characterized by their Noise Equivalent Temperature Difference (NETD), which represents the smallest temperature difference that can be detected above the detector's own noise. Advancements in materials science and sensor technology continue to improve the performance and reduce the cost of thermal detectors, expanding their utility in both scientific and commercial fields.