An IR (Infrared) light camera works by detecting infrared radiation, which is a type of electromagnetic radiation invisible to the human eye, and converting it into a visible image.
Here's a breakdown of the process:
-
Infrared Radiation Emission: All objects emit infrared radiation, also known as heat, with the amount of radiation emitted directly related to the object's temperature. The hotter the object, the more infrared radiation it emits. The range that these cameras typically detect is within the 700-1000 nm range.
-
Lens and Optics: The IR camera uses specialized lenses and optics made from materials like germanium or silicon that are transparent to infrared radiation. These lenses focus the infrared radiation onto the camera's sensor.
-
Infrared Sensor: The heart of an IR camera is its infrared sensor, which is an array of detectors sensitive to infrared radiation. These detectors are typically microbolometers, which are tiny thermal sensors that change resistance when heated by infrared radiation.
-
Signal Processing: The changes in resistance in the microbolometers are converted into electrical signals. These signals are then processed by the camera's internal electronics.
-
Image Creation: The processed signals are used to create a thermal image, also known as a thermogram. This image represents the temperature distribution of the objects in the camera's field of view.
-
Color Mapping (Thermography): The camera assigns different colors to different temperature ranges. This color mapping allows users to easily visualize the temperature differences in the scene. For example, hotter objects may be displayed in red or white, while cooler objects may be displayed in blue or green. This results in the thermography that visualizes heat variations.
In summary, an IR camera detects the infrared radiation emitted by objects, converts it into electrical signals, and then processes these signals to create a visible image that represents the temperature distribution of the scene. This image is often color-coded to make it easier to interpret temperature differences.
