Thermal imaging dataset from mild steel plate inspected by pulsed thermography with interface differences

10.60933/PRDR/HJYNZBYU, SamuelSamuelYU0000-0002-5615-9956The Hong Kong Polytechnic UniversityCHUNG, Winnie Wai-szeWinnie Wai-szeCHUNGThe Hong Kong Polytechnic UniversityLAU, Tom Chun-waiTom Chun-waiLAU0000-0003-2144-659XThe Hong Kong Polytechnic UniversityLAI, Wallace Wai-lokWallace Wai-lokLAI0000-0002-0696-6741The Hong Kong Polytechnic UniversitySHAMSHAM0000-0001-6424-5734Janet Fung ChuHO, Chun YiuChun YiuHOThe Hong Kong and China Gas Company LimitedThermal imaging dataset from mild steel plate inspected by pulsed thermography with interface differencesPolyU Research Data Repository2025EngineeringFlat Bottomed HolePulsed ThermographyInfrared ThermographyNon-destructive TestingYU, SamuelSamuelYUThe Hong Kong Polytechnic UniversityLAI, Wallace Wai-lokWallace Wai-lokLAIThe Hong Kong Polytechnic University2025-04-162026-01-12Survey Data10.1016/j.ndteint.2023.10279150189430150032628550055153049875989749701233849561330349362329449098934951237611450816214550830544850730091650643338150561050250431683550401010648537801748790553549242587746670718847275119147597041147891559647024763548825368247850246847637598247912645548074866548154295248161710648221829648310997548465721648669901448738755148746125348734320448809561048796574150094379650079168050050345150100256450084676350062005049599912448465522247402896446779093146724313946623109546636708346850412646704027246740965847933010547445871447554778747517551147423807447486676447445666247525873548934603148675302248823214248752638248721089848791303248853804448847316750581810850584452550531897050495883850519205650440107050424855050237071751051006150887978250957421048827563649257585549459990049558701849620646650626456250587248250631220950659026150595211250573815750485409950459752642397application/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/zipapplication/ziptext/markdown2.0CC BY-NC 4.0Abstract This dataset presents a thermal imaging dataset from mild steel sample that were inspected by pulsed thermography with the goal of detecting and characterizing external corrosion of metallic underground utilites (manually milled flat bottom holes representing corroded regions). The pulsed thermography experiment was applied to two mild steel plates with the dimensions of 150 mm (length) × 150 mm (width) × 10 mm (thick). The first plate contains 11 circular milled flat-bottomed holes with residual thicknesses of 1 mm 3 mm and 5 mm and lateral size of 5 mm, 10 mm, 15 mm and 20 mm while the second plates contains 9 rectangular milled flat-bottomed holes with residual thickness of 3 mm, 6 mm and 8 mm, width of 2 mm, 4 mm, 7 mm and uniform height of 20 mm. 6 sets of data were collected for both plates with half of them having steel-air interface and the other half having steel-sand interface. A pair of ZOOM PRO HD Elinchrom Digital RX photographic flashes (3 kJ per flash lamp) were used to generate the heat pulse (4 ms duration), an A655sc FLIR infrared camera using ResearchIR software to record the thermal images 450mm from the mild steel sample. Finally, the dataset proposed consists of 6 sequences of approximately 8000 images of 640 × 480 pixels each. Methods  Test Sample This dataset is collected using pulsed thermography method. Sequential IR image data were obtained using a pulsed-heating TNDT system. In the experiment, two 150 mm (length) × 150 mm (width) × 10 mm (thick) mild steel plate was machine-milled with 11 and 9 flat-bottom holes, respectively. The plate milled with circular holes had varying diameters (20 mm, 15 mm, 10 mm, 5 mm) and residual thicknesses (1 mm, 3 mm, 5 mm) while the plate milled with rectangular holes had varying width (2 mm, 4 mm, 7 mm) and residual thickness (3 mm, 6 mm, 8 mm) to imitate the various defects in a pipe wall. To model the environment of a buried metallic pipe, 3 sets of data were collected while the holes were filled with sand. Instrumentation A pair of flash lamps, which were directed towards the rear surface of the plate, was used for excitation (at t = 0 s). The plate was painted with a thin layer of black flat paint so that its emissivity was as close as possible to that of a blackbody. The change in temperature of the surface was monitored by a high-speed, long-wave infrared camera (7–14 μm) with a 640 × 480 pixel microbolometer at a frame rate of 50 Hz for 2.5 minutes after the application of the pulse. The instrument specifications and parameters used for the acquisition of the thermogram are provided in the table below. <table style="border-collapse: collapse; border: none; width: 100%;"> <tbody> <tr> <td style="border: 1pt inset black; padding: 0.75pt; width: 51.1158%;"> Experimental Equipment </td> <td colspan="2" style="width: 48.7721%; border-top: 1pt inset black; border-left: none; border-bottom: 1pt inset black; border-right: 1pt solid windowtext; padding: 0.75pt;"> Acquisition Parameters </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> Thermal stimulation: </td> <td rowspan="3" style="border-top: none; border-bottom: none; border-left: none; border-image: initial; border-right: 1pt inset black; padding: 0.75pt; width: 40.8125%;"> Sampling rate </td> <td rowspan="3" style="border:none;border-right:inset black 1.0pt;padding:.75pt .75pt .75pt .75pt;"> 50 Hz </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> Photographic Flashes: ELINCHROM ZOOM Pro HD </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> Pulse duration: 4 ms thermal pulse, </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> Deposited energy: 3 kJ/flash (Total energy deposited 6 kJ) </td> <td style="border-top: 1pt inset black; border-right: 1pt inset black; border-bottom: 1pt inset black; border-image: initial; border-left: none; padding: 0.75pt; width: 40.8125%;"> Acquisition duration </td> <td style="border:inset black 1.0pt;border-left:none;padding:.75pt .75pt .75pt .75pt;"> 160 s </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> Thermographic monitoring </td> <td rowspan="3" style="border-top: none; border-bottom: none; border-left: none; border-image: initial; border-right: 1pt inset black; padding: 0.75pt; width: 40.8125%;"> Time interval </td> <td rowspan="3" style="border:none;border-right:inset black 1.0pt;padding:.75pt .75pt .75pt .75pt;"> 20 ms </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> FLIR A655sc, FOV 25°, </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> 640 × 480 pixel microbolometer, </td> </tr> <tr> <td style="border-right: 1pt inset black; border-bottom: 1pt inset black; border-left: 1pt inset black; border-image: initial; border-top: none; padding: 0.75pt; width: 51.1158%;"> 16-bit data, NETD: <30 mK, spectral range: 7.5-14.0 µm </td> <td style="border-top: 1pt inset black; border-right: 1pt inset black; border-bottom: 1pt inset black; border-image: initial; border-left: none; padding: 0.75pt; width: 40.8125%;"> Total number of frames </td> <td style="border:inset black 1.0pt;border-left:none;padding:.75pt .75pt .75pt .75pt;"> 8000 </td> </tr> </tbody> </table>  Thermal imaging dataset from mild steel plate inspected by pulsed thermography with interface differences https://doi.org/10.60933/PRDR/NBJJEM Data Collection Method The infrared camera recorded the thermal evolution on the surface of the inspected mild steel sample for around 2.5 minutes (approximately 160 s) at a 50 frames per second sampling rate, before applying a heat pulse, during the heat pulse, and during cooling. The experiment was performed from the front faces of the specimens with two types of boundary interfaces at the back of the specimen (sand-steel or air-steel) and each sequence was labelled and saved into an independent file. Description of the data and file structure Every .zip file contains 1000 .csv files. They are labelled as MS-facq-50Hz-interfaceMaterial-shapeOfHoles-collectionSetNumber_Img-frames. This tagging scheme describes the sample material, the acquisition side of the inspection taken, the acquisition frequency used, the interface material of the steel plate, the shape of the milled flat-bottomed holes on the plate, the number of sets regarding the sample plate and interface, as well as the whole number of frames from the image sequence and the number of each frame within the sequence.Underground Utility Survey LaboratoryInnovative Technology Fund by HKSAR GovernmentPRP/014/19FXThe Hong Kong and China Gas Company LimitedPRP/014/19FX