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Construction of Active Infrared Detection System

Feb. 27, 2021

Infrared non-destructive testing technology is based on the principle of infrared radiation. This technology uses measurement and analysis of infrared radiation to diagnose and inspect tested samples, such as equipment or materials. The infrared detection system combines the photoelectric system. The system presents the measurement signal through the thermal image obtained by the infrared detection device. Infrared thermal imaging detection technology is fast, non-contact, full-field and non-destructive, which is widely used in aerospace, machinery, industrial production and other fields.


In order to achieve the ideal capabilities of detection and resolution, some detectors need to work at low temperatures. Therefore, some infrared detection systems use a refrigerator to cool the detectors. When the measured object is in a thermal equilibrium state, it is not easy to detect and analyze its internal conditions. At the moment, an external thermal excitation source is usually used to apply thermal excitation to the measured object. Therefore, infrared detection systems can be divided into active detection systems and passive detection systems.


Active infrared detection system mainly includes a photoelectric detector, thermal excitation source and other parts. The Infrared thermal imaging camera is the central component of the infrared thermal imaging system, which integrates an infrared optical system, photodetector, signal amplifier and signal processing unit. The size of the infrared thermal imager's field of view is determined by the infrared optics and its position. Sometimes, according to the needs of the application, it is necessary to add the infrared filter of the corresponding wave band to the infrared camera.


At present, the commonly used excitation sources are flash lamps, infrared halogen lamps, lasers, etc. Among them, the laser can perform heating of measured object in point, line, and surface way. It also has the advantages of fast speed, low thermal noise, high efficiency and high repeatability. In particular, semiconductor lasers have been widely used in the detection field. Their advantages are small size, lightweight, and low energy consumption.


When using a fiber-coupled semiconductor laser heating system, in order to improve the coupling efficiency of the light source, a collimating lens is usually used to align the beam of the light source to the fiber axis. And then a converging lens is used to shape the light beam, compress the divergence angle, and improve the symmetry and spot shape of the far-field. At the same time, the heating power and heating time are effectively adjusted and controlled.


The construction of the active infrared system is mainly to study how to use infrared technology in the detection process. The commonly used subassemblies are infrared thermal imaging cameras and thermal excitation sources. CLZ Precision Optics Co., Ltd. provides related optical components for active infrared detection systems, such as optical lenses and optical filters. At the same time, our company also provides optical domes, optical windows, optical prisms and optical mirrors. Looking forward to your inquiry, please contact