Active thermography for the analysis and conservation of Roman lead pipes at the Baia archaeological park

• Active Thermography (AT) was applied for the first time to analyze Roman lead pipes. • Comparison of three AT methods to analyze Roman lead pipes pre and post restoration. • Case study on the Pisones fistula, a Roman lead pipe of historical significance. • Evaluation of three thermal data processing techniques for analyzing lead pipes. The conservation and study of ancient cultural heritage artifacts, particularly those that have been buried or weathered over time, present considerable challenges. Among these artifacts, Roman lead pipes ( fistulae plumbeae ) require non-destructive methods to assess their condition and reveal hidden details. This study explores the application of active thermography (AT) as a non-destructive method for analyzing these artifacts, focusing on three distinct thermal stimulation techniques: hot air, long light pulse, and short light pulse. The analysis was conducted on three fistulae plumbeae from the Baia Archaeological Park, including a detailed case study on the Pisones fistula . Advanced thermal data processing techniques, such as Maximum Thermal Gradient, Thermal Recovery, and Principal Component Thermography, were employed to assess the conservation state of these pipes. The findings demonstrate that AT effectively identifies areas of deterioration, encrustations, and impurity accumulation, while also providing insights into the impact of restoration interventions. This pioneering research highlights the potential of infrared thermography for the non-destructive analysis of Roman lead pipes and underscores the broader applicability of thermal imaging technologies in cultural heritage conservation.