Thermal imaging dataset from buried ductile iron pipe inspected by in-pipe thermography under convective heatingdoi:10.60933/PRDR/NBJJEMPolyU Research Data Repository2025-05-171YU, Samuel; HO, Marco Kin Pan; LAI, Wallace Wai-lok; SHAM, Janet Fung Chu; HO, Chun Yiu, 2025, "Thermal imaging dataset from buried ductile iron pipe inspected by in-pipe thermography under convective heating", https://doi.org/10.60933/PRDR/NBJJEM, PolyU Research Data Repository, V1Thermal imaging dataset from buried ductile iron pipe inspected by in-pipe thermography under convective heatingdoi:10.60933/PRDR/NBJJEMYU, SamuelHO, Marco Kin PanLAI, Wallace Wai-lokSHAM, Janet Fung ChuHO, Chun YiuYU, SamuelHO, Chun YiuLAI, Wallace Wai-lokSHAM, Janet Fung ChuSHAM, Janet Fung ChuHO, Chun Yiu2022-01-20Hin Keng, Shatin, New Territories, Hong KongFLIR Research StudioPRP/014/19FXPRP/014/19FXPolyU Research Data RepositoryYU, SamuelLAI, Wallace Wai-lokYU, Samuel2025-05-08EngineeringFlat Bottomed HoleConvective HeatingIn-pipe InspectionInfrared ThermographyNon-destructive Testing<p style='margin-top:0cm;margin-right:0cm;margin-bottom:8.0pt;margin-left:0cm;font-size:11.0pt;font-family:"Aptos",sans-serif;'><span style='font-size:16px;font-family:"Times New Roman",serif;'>This dataset presents a thermal imaging dataset from a buried ductile iron pipe that were in-pipe inspected by infrared thermography with convective heating by hot air to validate whether convective heating is a reliable way in detecting and characterising external corrosion of metallic underground utilities (manually milled flat bottom holes on the outer pipe wall representing corroded regions). A heat blower was set to 50 °C, and the hot air was blown into the pipe with a 400 mm diameter at a velocity of 0.8 m/s for approximately 140 seconds. The pipe is 1.5 m long with a wall thickness of 8 mm, with an initial temperature of 22.3 °C. 36 flat-bottom holes were milled on the outer pipe wall, spread in 6 circumferential rings and angular direction. Three types of milled shapes with three different lateral sizes of 75 mm, 50 mm, and 25 mm were designed with varying residual thickness ranging from 1.7 mm to 4.4 mm. A Tau2 infrared camera in tunnel-view (facing frontward) is used to record the thermal images at an 8.7 frames per second sampling rate. Finally, the dataset proposed consists of 1 sequence of 4446 images of 640 x 512 pixels.</span></p>Survey DataThermal imaging dataset from a buried ductile iron pipe inspected by in-pipe thermography under convective heating https://doi.org/10.60933/PRDR/NBJJEM Data Collection Method The infrared camera recorded the thermal evolution on the inner surface of a buried ductile iron (DI) pipe with an inner diameter of 400 mm for around 8.5 minutes (approximately 511 seconds) at an 8.7 frames per second sampling rate, before applying forced convective heating, during convective heating, and cooling. This pipe has a cover depth of 1.5m and was attached to a riser at the end of the pipe. The hot air is then applied through the riser from the surface with an initial entrance temperature of 50 °C and an initial exit temperature of 25.5 °C. The pipe is then heated up for around 140 seconds. The hot air has a final entrance temperature of 57.6 °C and a final exit temperature of 38.7 °C. The hot air has an average of 0.8 m/s throughout the whole heating period. Description of the data and file structure Every .zip file contains 1000 .csv files except the last zip, which only includes 446 .csv files. They are labelled as DI-IP-TV-9Hz-sand_Img-frames. This tagging scheme describes the sample material (DI), the inspection mode taken (In-pipe), the view of the acquisition (Tunnel view), the acquisition frequency used, the interface material of the pipe (Sand-Iron) and the number of each frame within the sequence.DI-IP-TV-9Hz-sand_0-999.zipapplication/zipDI-IP-TV-9Hz-sand_1000-1999.zipapplication/zipDI-IP-TV-9Hz-sand_2000-2999.zipapplication/zipDI-IP-TV-9Hz-sand_3000-3999.zipapplication/zipDI-IP-TV-9Hz-sand_4000-4445.zipapplication/zipREADME.mdtext/markdownSchematic drawings of the design defects.pngThis is a schematic drawing of the design pipeline illustrating the distribution of the milled flat-bottomed holes on the exterior of the pipeline. image/pngTable of Defects on 400 mm pipe.pngThis is a table of the milled flat-bottomed holes distributed on the exterior of the pipeline with their angular direction and distance from the pipe entrance. The milled flat bottom holes are labelled with their ring numbers (R1-R6), lateral dimension (25 mm, 50mm, 75 mm), shape (Circle - C, Square - S, and Peanut - I), and residual thickness (1.7 mm - 4.4 mm)image/png