Key Technical Parameters and Their Definitions
NETD (Noise Equivalent Temperature Difference)
Definition: The smallest temperature difference a thermal camera can detect between two adjacent points, measured in millikelvins (mK). Lower NETD values represent higher sensitivity. For example, a camera with NETD 40 mK can distinguish a target at 36.04°C from a background at 36.00°C.
Spatial Resolution
Definition: The ability of the camera to resolve fine details of an object, determined by sensor pixel pitch and optics. Expressed in milliradians (mrad) or Instantaneous Field of View (IFOV). A smaller IFOV means sharper details at longer distances.
Thermal Sensitivity vs. Resolution
Sensitivity (NETD) measures the ability to detect small temperature differences, while resolution measures the ability to distinguish small physical details. Both factors are critical in evaluating camera performance.
Wavelength Range
Definition: Thermal cameras generally operate in LWIR (8–14 μm) or MWIR (3–5 μm). LWIR is best for passive human detection, while MWIR is more suitable for high-temperature industrial applications.
