Creating a Liquid Transfer Electrical Detector (LTED) to conduct an in-situ, non-destructive examination of the coating loss and weathering of white marble artifacts

Abstract

A new testing instrument and method were designed to assess the weathering and coating of stone cultural relics. The test instrument applied the principle of transferring liquid to porous materials and monitoring the mass-transfer process in conjunction with impedance-testing instruments. The analysis of liquid transport through a material was based on the impedance–time curve, followed by an analysis of the material properties. The laboratory results indicated that the maximum values of conductivity and capacitance (G-max and C-max, respectively) were linearly and positively correlated with the porosity of white marble. Field experiments revealed that white marble components with higher G-max experienced more severe weathering, leading to a faster decrease in conductivity (G) and a larger difference in conductivity (ΔG). A higher level of aging resulted in better conductivity of components coated with lower-conductivity materials. The test method was nondestructive, portable, highly sensitive, and exhibited good stability during the testing process. This makes it promising for characterizing the properties of the insulating materials found in heritage sites, such as stone carvings, ceramics, and wall paintings.