Non-destructive testing (NDT) refers to a test that examines the condition of the external and internal structures of the object (material, structure, part, etc.) to be inspected without altering its original form or function. Preventing component failure is essential both in manufacturing and in service, as damage seriously reduces the stability of the structure. They are applying effective and reliable non-destructive testing and structural health monitoring to improve economics and availability. Previously, visual inspection (VT), liquid penetration testing (LPT), magnetic particle testing (MPT), ultrasonic inspection (UT), acoustic emission testing (AE), eddy current testing (ECT), radiographic testing (RT), and thermographic testing (TT) are being studied and applied as non-destructive inspection technologies [5; 7; 8; 9; 10]. Among them, the TT has shown great potential and advantages regarding fast inspection speed and the possibility of detecting internal defects through heat conduction through external energy excitation. Additionally, advances in signal and image processing techniques can provide results with high resolution and sensitivity [11; 12]. In general, infrared thermographic non-destructive testing uses an active thermography method that uses an external heat source to apply energy to the surface of the test specimen. Representative active thermography includes optical-infrared thermography, eddy current thermography, ultrasonic thermography, laser thermography, and thermography methods utilizing other heat sources. Among them, optical-infrared thermography using optical devices is the most widely used [13; 14]. Optical-infrared thermography methods include pulse thermography (PT), which uses instantaneous heating using a high-power flash lamp, and lock-in thermography (LIT), which uses sinusoidal periodic heating using a halogen lamp. Since both measurement methods use heating using an optical source, the energy becomes weaker as the distance from the center of the optical source increases, resulting in uneven energy supply. To improve these limitations, research has been conducted on various signal and data processing algorithms. Representative IR signal processing techniques include Fourier transform-based Pulse Phase Thermography (PPT) [15]. In addition, there are Principal Component Thermography (PCT) [16] using principal component analysis, Thermographic Signal Reconstruction (TSR) [17] using mathematical derivatives, and Wavelet Thermography (VT) [18] based on Wavelet transform. Various studies have been conducted to expand the above signal processing technique and have been published in the literature [19]. However, research on the developing devices and methods that can provide fundamentally uniform heating is insufficient. In addition, with the development of materials, electronics, and signal processing technology, infrared (IR) cameras are becoming more economical, and their resolution and efficiency are improving. Non-destructive testing requires accurate temperature measurement and stable IR image acquisition, and the prevention and supplementation of various error-causing factors are necessary. Infrared energy emitted from the inspection object is converted into temperature through digital levels detected by an IR camera. During the temperature conversion process, imperfections in the black body considered in IR camera calibration, errors in detector non-uniformity correction (NUC), and emissivity measurement errors may occur, and the proper emissivity knowledge, calibration, and correction of emissivity are required [20; 21; 22; 23]. In this study, an equivalent array lamp was designed, manufactured, and applied to the study for uniform heating during digital lock-in thermography testing. In addition, test samples simulating defect conditions of various sizes and depths and reference sampleswithout defects were produced.