Pulsed infrared thermographic study of a Chinese Bronze Lei

In this paper, pulsed infrared thermography is applied to the study of a mold casting Chinese bronze lei 罍 dated to the late Shang dynasty (c.a.1250–1050 BC), currently housed in the Capital Normal University Museum. Many spacers and a defective area of this ancient bronze are partly covered with repair material. By analyzing thermographic images using a one-layer thermal diffusion model, it is found that the spacers were specifically made for this bronze. The thickness of the repairing material in the defective area is measured using thermal quadrupole modelling in multi-layer materials. This is the first application of this method to the field of cultural heritage conservation. These results provide a deeper understanding of the manufacturing process of ancient Chinese bronzes from the viewpoint of archaeological research. They also help assess the repair status from the conservation viewpoint.