Investigation of thermal imaging sampling frequency for eddy current pulsed thermography

• For ECPT, different sampling rates thermal images are applied for characterization.
• Feature robustness versus different sampling rates.
• Proper IR camera sampling rates are reported.
• Blind source separation defect detection is used for comparison.

Eddy Current Pulsed Thermography (ECPT) is an integrative Non-Destructive Testing and Evaluation (NDT&E) technique that has been applied for defect and material characterization of conductive material and components. Thermal transient images provide rich information for decision making. However, high sampling rates of a thermal camera creates high cost and will generate a large of amount of data which is difficult for remote monitoring in terms of computational efficiency and data communication. This paper investigates the impact of thermal image sampling rates versus feature extraction for defect characterization. After introduction of Eddy Current Pulsed Thermography (ECPT), different sampling rates of thermal images are applied for different characterization. Based on the feature robustness versus different sampling rates, appropriate sampling rates are reported. The impact of using high end and low end thermal cameras for ECPT non-destructive evaluation are discussed.