Corrosion thickness measurement of bronze ware by infrared thermography

In order to measure the thickness of the rusted bronze layer quickly and accurately, an active infrared thermal imaging technique is developed. Pulse flash lamp was used to excite the surface of the specimen, and infrared thermal imager was used to record the temperature decay of the specimen surface before and after flash. This paper presents a pulse thermal imaging multi-layer analysis method (PTI-MLA) which consists of a pulsed thermal imaging (PTI) system to acquire experimental data and a multilayer analysis (MLA) data-processing algorithm to derive parameters of the corroded bronze. This paper studies a bronze pot fragment from the China’s Spring and Autumn period excavated in Sujialong site, Hubei province. The corrosion thickness map of the fragment is calculated and analyzed by PTI-MLA method. Comparing the measured values with the CT scanning results, the error is less than 10%. The final result indicates that the PTI-MLA method can be used to measure the thickness of rust layer on the surface of bronze ware and obtain high-precision thickness images.