Analysis of the potential application of the shortwave infrared and near-infrared cameras to the weld temperature measurements
Temperature is a critical parameter in welding and related processes such as metal additive manufacturing. The real-time temperature measurement systems based on infrared thermal cameras have a potential to significantly improve the existing process control systems and, consequently, the quality of the welds and additive manufactured products. Conventional thermal cameras work in midwave (MWIR) and longwave infrared (LWIR) part of the infrared spectrum. They require sophisticated sensor systems and special optics. Cameras that work in the part of the infrared spectrum which is closer to visible light (shortwave infrared SWIR and near-infrared NIR) are less sensitive at lower temperatures, but potentially may be used for temperature measurements at temperatures typical in welding. They can use regular glass optics and their sensors do not require cooling to low temperatures and are made of less sophisticated materials which makes them significantly cheaper and easier to use. These features of the SWIR and NIR camera systems indicate their potential for the real-time welding and metal additive manufacturing temperature measurement systems. The objective of the project is to study the ability of the camera systems working in the SWIR and NIR spectrum ranges to capture the thermal emission during welding and provide temperature measurement.