Cryogenic refrigerator is integrated in the imaging sensor of the long range cooled thermal camera. This device can cool down the sensor. The purpose of lowering the detector temperature is to make the thermal noise signal lower than the imaging signal.
Cooled thermal imagining camera are most sensitive to small temperature differences in the scene, detect the smallest temperature differences between objects. This thermal imaging camera can perform imaging in the mid-wave infrared or mid-wave infrared band of the spectrum.
Thermal contrast is the signal change caused by the target temperature change. The higher the thermal contrast, the easier it is to detect targets that are not too different from the background temperature. Generally speaking, the contrast of mid-wave infrared thermal imaging cameras at night is more vivid than that of other infrared thermal imaging cameras.
The temperature sensitivity is different between uncooled thermal camera and long range cooled thermal camera.
The temperature sensitivity of an uncooled thermal imager is generally 50mk, while that of a refrigerated thermal imager is 25mk. When the refrigerated infrared thermal imager is working, the refrigerator first works to reduce its own temperature, so that when detecting other objects, the sensitivity is higher, the accuracy is higher, the error is smaller, and the detection temperature range is wider.
These aspects of uncooled infrared thermal imaging cameras are beyond reach, especially the non-uniformity of uncooled infrared focal plane arrays has a greater impact on measurement errors.
The refrigerated infrared thermal imager needs a refrigerator to cool down when it is working, so it consumes more energy and consumes more power than an uncooled thermal imager.
The service life of a refrigerated thermal imaging camera is closely related to its own refrigerator. The working time of the refrigerator is related to the service life of the thermal imaging camera. In comparison, the service life of an uncooled thermal imaging camera is longer than that of a refrigerated thermal imaging camera, but as the use time increases, the parts age and the measurement accuracy will decrease.
Generally speaking, cooled infrared thermal imaging cameras are expensive, while uncooled thermal camera are relatively inexpensive.
Compared with traditional monitoring systems, uncooled thermal imaging cameras have a much simpler structure, lower cost, and greatly improve monitoring efficiency. Now they are widely used in military, border and coastal defense, mines, airports, railways and other perimeter monitoring, and Maritime traffic.
With the independent research and development of the movement, the cost of thermal imaging cameras has been further reduced, and thermal imaging cameras have gradually begun to work with traditional monitoring in civilian fields, such as fishery, agriculture and animal husbandry.