EEN thermische camerasensor (ook wel een genoemd infraroodsensor of IR-sensor) is the core component of a thermal imaging device that detects infrared radiation (warmte) emitted by objects and converts it into an electronic signal. This signal is then processed to create a visual representation of temperature differences, known as a thermogram. In tegenstelling tot camera's met zichtbaar licht, thermische sensoren “zie je wel” heat rather than light, enabling them to operate in total darkness, through smoke, mist, or other obscurants.

---

Hoe het werkt

1. Infrared Detection:
   • All objects above absolute zero (-273° C) emit infrared radiation.
   • The sensor detects wavelengths in the langegolf infrarood (Lwir) spectrum (8–14 μm), which corresponds to the heat emitted by most everyday objects.
2. Heat-to-Signal Conversion:
   • The sensor’s pixels absorb infrared radiation, causing a temperature change.
   • This change is converted into an electrical signal (voltage or resistance).
3. Beeldverwerking:
   • Signals are translated into a thermal image, with colors or grayscale representing temperature variations (Bijv., red = hot, blue = cold).

---

Key Types of Thermal Sensors

Type	Hoe het werkt	toepassingen
Microbolometer	Uses tiny heat-sensitive resistors (pixels) that change resistance with temperature. Common in uncooled systems.	Drones, veiligheid, industriële inspecties.
Photon Detector	Uses semiconductor materials (Bijv., InSb, HgCdTe) that generate electrons when exposed to IR. Requires cooling (cryogenic or Stirling cooler).	Leger, scientific research, astronomy.
Pyroelectric	Detects rapid temperature changes (Bijv., motion sensing). Not for static imaging.	Motion detectors, intruder alarms.

---

Belangrijke specificaties

1. Resolutie:
   • Pixel count (Bijv., 160× 120, 320×240, 640× 512). Higher resolution = finer detail.
2. Thermische gevoeligheid (Netd):
   • Geluidsequivalent temperatuurverschil: Lower values (<50 mK) mean better ability to detect small temperature differences.
3. Spectraal bereik:
   • Lwir (8–14 μm) for most consumer/industrial use; SNEL (3–5 μm) for high-temperature or gas detection.
4. Framesnelheid:
   • Speed of image capture (Bijv., 9 Hz for basic models, 60 Hz for high-speed applications).
5. Temperatuurbereik:
   • From -40°C to +2000°C+ (depends on sensor type).

---

Example Sensors

1. FLIR BOSON (Microbolometer):
   • 640× 512 resolutie, Netd <50 mK, used in drones and handheld thermal cameras.
2. Teledyne flir tau 2 (Microbolometer):
   • 640× 512 resolutie, ruggedized for military/industrial use.
3. Seek Thermal CompactPRO (Microbolometer):
   • 320×240 resolution, smartphone-compatible.
4. Sofradir Quantum Well Infrared Photodetector (QWIP):
   • High-end MWIR sensor for gas detection and aerospace.

---

toepassingen

• Brandbestrijding: Detect hotspots through smoke.
• Medische beeldvorming: Screen for fevers or inflammation.
• Bouwinspecties: Find insulation leaks or electrical faults.
• Wildlife monitoring: Track animals at night.
• Automobiel: Night vision systems for cars.
• Industrieel: Monitor machinery for overheating.

---

Beperkingen

• Kosten: High-resolution sensors (Bijv., 640× 512) are expensive.
• Milieu -interferentie: Regen, stof, or reflective surfaces (Bijv., glas) can distort readings.
• No Visible Detail: Thermal images lack texture/color seen in visible-light photos.

---

Radiometric vs. Non-Radiometric Sensors

• Radiometric: Provide temperature data for each pixel (used in inspections and analytics).
• Non-Radiometric: Show heat gradients but no exact temperature values (used in basic surveillance).

---

Cooled vs. Uncooled Sensors

Kenmerk	Cooled Sensors	Uncooled Sensors
Koelmethode	Cryogenic or Stirling cooler (to ~-200°C).	No cooling (operate at ambient temp).
Gevoeligheid	Extremely high (detect <10 mK differences).	Gematigd (50–100 mK).
Kosten	Zeer hoog ($10,000+).	Betaalbaar ($500-$5,000).
Gebruiksscenario's	Leger, gas detection, scientific research.	Consumer drones, veiligheid, HVAC inspections.

---

Material Science

• Lens Material: Germanium (Zendt IR -licht uit) or chalcogenide glass.
• Pixel Array: Vanadiumoxide (Vox) or amorphous silicon (a-Si) for microbolometers.

---

Future Trends

• Miniaturisatie: Smaller sensors for smartphones and wearables.
• AI Integration: On-sensor analytics for automatic anomaly detection.
• Multi-Spectral Sensors: Combine thermal, visuele, and LiDAR data.

---

In het kort, een thermische camerasensor is de “eye” that sees heat, enabling machines to perceive the world beyond visible light. Its capabilities are shaped by resolution, gevoeligheid, and cooling requirements, making it a critical tool in fields from emergency response to energy efficiency.