Infrared (IR) radiation is the key to thermal imaging, which lets us “see” heat instead of visible light. Here’s how it works:
- Heat Emission from Objects
- All objects above absolute zero emit infrared radiation.
- Warmer objects emit more IR and at shorter wavelengths than cooler ones.
- IR Detection
- A thermal imaging camera uses special infrared sensors (like microbolometers) that respond to IR wavelengths, usually in the 8–14 μm range.
- These sensors measure the intensity of incoming IR radiation from each point in the scene.
- Temperature Mapping
- The camera converts the IR measurements into temperature values.
- Software assigns colors to these temperatures, producing a false-color image (e.g., red for hot, blue for cool).
- Applications
- Security & Surveillance: Detect intruders in darkness or smoke.
- Firefighting: Locate people or hotspots in smoky environments.
- Industrial Inspection: Find overheating machinery or electrical faults.
- Medical Use: Monitor inflammation or poor blood flow.
- Wildlife Observation: Track animals at night without disturbing them.
- Advantage
- Works in complete darkness, through smoke, fog, or light foliage, since it relies on heat, not reflected visible light.