Challenges of obtaining reliable high temperature measurements in plasma transferred arc welding
Tonya Wolf, PhD student in Materials Engineering
High temperature measurements of PTAW (plasma transferred arc welding) coatings deposited in-situ are required in order to optimize the process. There is wide interest in obtaining high temperature measurements for other high temperature processes using infrared thermography. However, the reliability of the quantitative data is often in question. Changes in emissivity with temperature, surface condition and phase change challenge the credibility of infrared results. In this presentation, the methodology developed and applied to PTAW in order to generate reliable temperature measurements of the surface of the deposit upon cooling after the arc is extinguished, will be described. The methodology applies the coupled use of differential scanning calorimetry, laser reflectance pyrometry, infrared thermography and mathematical modeling.
High temperature measurements of PTAW (plasma transferred arc welding) coatings deposited in-situ are required in order to optimize the process. There is wide interest in obtaining high temperature measurements for other high temperature processes using infrared thermography. However, the reliability of the quantitative data is often in question. Changes in emissivity with temperature, surface condition and phase change challenge the credibility of infrared results. In this presentation, the methodology developed and applied to PTAW in order to generate reliable temperature measurements of the surface of the deposit upon cooling after the arc is extinguished, will be described. The methodology applies the coupled use of differential scanning calorimetry, laser reflectance pyrometry, infrared thermography and mathematical modeling. 
