TY - CHAP A1 - Hartmann, Jürgen A1 - Dobhan, Alexander A1 - Engelmann, Bastian A1 - Eberhardt, Lars A1 - Heusinger, Moritz A1 - Raab, C A1 - Schleif, Frank-Michael A1 - Türk, M. T1 - Optimierung von Prozessen und Werkzeugmaschinen durch Bereitstellung, Analyse und Soll-Ist-Vergleich von Produktionsdaten: Digitalkonferenz Y1 - 2020 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Thuillier, G. A1 - Foujols, T. A1 - Bolsée, D. A1 - Gillotay, D. A1 - Hersé, M. A1 - Petermanns, W. A1 - Decupyer, W. A1 - Mandel, H. A1 - Sperfeld, P. A1 - Taubert, Dieter Richard T1 - SOLAR/SOLSPEC BT - Scientific objectives, instrument performances and its absolute calibration using a blackbody as primary standard source JF - Solar Physics Y1 - 2009 UR - http://permalink.bibkatalog.de/BV021245164 IS - 257 SP - 185 EP - 213 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Lowe, D. A1 - Machin, Graham A1 - Sadli, M. A1 - Yamada, Y. T1 - Thermodynamic temperature determinations of Co-C, Pd-C Pt-C and Ru-C eutectic fixed-points cells JF - Metrologia Y1 - 2006 UR - http://permalink.bibkatalog.de/BV012573233 VL - 43 IS - 2 SP - 78 EP - 83 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Machin, G. A1 - Bloembergen, P. A1 - Sadli, M. A1 - Yamada, Y. T1 - A concerted international project to establish high-temperature fixed-points for primary thermometry JF - International Journal of Thermophysics Y1 - 2007 UR - http://permalink.bibkatalog.de/BV013298193 IS - 28 SP - 1976 EP - 1982 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Reichling, M. ED - Nazaré, H. ED - Neves, A.J. T1 - Thermal transport in diamond T2 - Properties and growth of diamond Y1 - 2001 UR - https://books.google.de/books?id=jtC1mUFZfQcC&printsec=frontcover PB - Institution of Electrical Engineers CY - London ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Sadli, M. A1 - Anhalt, Klaus A1 - Schiller, S. T1 - Thermal effects in the BB3200pg on M-C eutectic implementation JF - International Journal of Thermophysics Y1 - 2009 UR - http://permalink.bibkatalog.de/BV013298193 IS - 30 SP - 69 EP - 76 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - New Developments in High-Temperature Measurement Techniques JF - International Journal of Electrical and Computer Engineering Systems Y1 - 2014 VL - 5 IS - 2 SP - 63 EP - 67 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Engert, J. A1 - Fellmuth, B. A1 - Fischer, Joachim A1 - Hollandt, Jörg A1 - Tegeler, E. A1 - Seidel, J. T1 - Die internationale Temperaturskalen BT - ITS-90 und PLTS-2000 JF - PTB Mitteilungen Y1 - 2007 UR - http://permalink.bibkatalog.de/BV035078972 VL - 117 IS - 3 SP - 236 EP - 242 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Fischer, J. A1 - Johannsen, U. A1 - Werner, L. T1 - Analytical model for the temperature dependence of the spectral responsivity of silicon JF - J. Opt. Soc. Am. B Y1 - 2001 IS - 18 SP - 942 EP - 947 ER - TY - JOUR A1 - Höfflin, Dennis A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Versch, Alexander A1 - Hartmann, Jürgen T1 - Active thermography for in-situ defect detection in laser powder bed fusion of metal JF - Journal of Manufacturing Processes N2 - Additive manufacturing (AM) has revolutionized production by offering design flexibility, reducing material waste, and enabling intricate geometries that are often unachievable with traditional methods. As the use of AM for metals continues to expand, it is crucial to ensure the quality and integrity of printed components. Defects can compromise the mechanical properties and performance of the final product. Non-destructive testing (NDT) techniques are necessary to detect and characterize anomalies during or post-manufacturing. Active thermography, a thermal imaging technique that uses an external energy source to induce temperature variations, has emerged as a promising tool in this field. This paper explores the potential of in-situ non-destructive testing using the processing laser of a PBF-LB/M setup as an excitation source for active thermography. With this technological approach, artificially generated internal defects underneath an intact surface can be detected down to a defect size of 350 μm – 450 μm. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-57601 SN - 1526-6125 VL - 131 SP - 1758 EP - 1769 PB - Elsevier BV ER - TY - JOUR A1 - Höfflin, Dennis A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Manara, Jochen A1 - Hartmann, Jürgen T1 - Pixelwise high-temperature calibration for in-situ temperature measuring in powder bed fusion of metal with laser beam JF - Heliyon N2 - High-temperature calibration methods in additive manufacturing involve the use of advanced techniques to accurately measure and control the temperature of the build material during the additive manufacturing process. Infrared cameras, blackbody radiation sources and non-linear optimization algorithms are used to correlate the temperature of the material with its emitted thermal radiation. This is essential for ensuring the quality and repeatability of the final product. This paper presents the calibration procedure of an imaging system for in-situ measurement of absolute temperatures and temperature gradients during powder bed fusion of metal with laser beam (PBF-LB/M) in the temperature range of 500 K–1500 K. It describes the design of the optical setup to meet specific requirements in this application area as well as the procedure for accounting the various factors influencing the temperature measurement. These include camera-specific effects such as varying spectral sensitivities of the individual pixels of the sensor as well as influences of the exposure time and the exposed sensor area. Furthermore, influences caused by the complex optical path, such as inhomogeneous transmission properties of the galvanometer scanner as well as angle-dependent transmission properties of the f-theta lens were considered. A two-step fitting algorithm based on Planck's law of radiation was applied to best represent the correlation. With the presented procedure the calibrated thermography system provides the ability to measure absolute temperatures under real process conditions with high accuracy. Y1 - 2024 U6 - https://doi.org/10.1016/j.heliyon.2024.e28989 SN - 2405-8440 VL - 10 IS - 7 PB - Elsevier BV ER - TY - GEN A1 - Höfflin, Dennis A1 - Schiffler, Andreas A1 - Hartmann, Jürgen A1 - Sauer, Christian T1 - Dual Scan head approach for in-situ defect detection in laser powder bed fusion of metals - Dataset N2 - This dataset contains thermographic data from a study on in-situ defect detection in the Laser Powder Bed Fusion of Metals (PBF-LB/M) process. The data was collected using a novel experimental setup named Synchronized Path Infrared Thermography (SPIT), which employs a dual scan head configuration. One scan head directs the processing laser, while the second scan head positions the measurement field of an infrared (IR) camera. This setup allows for the precise analysis of the cooling behavior of the material decoupled from the immediate laser-material interaction zone. The experiments were conducted on pre-fabricated stainless steel (EOS StainlessSteel PH1, DIN 14540) samples with embedded, cylindrical subsurface defects of varying diameters. A single layer of metal powder was applied to these samples and then fused by the laser. The dataset includes a series of measurements where process parameters, specifically the volumetric energy density and the laser scanning speed, were systematically varied to assess their influence on defect detection reliability. The provided data consists of raw thermographic recordings, which capture the surface temperature distribution in the heat-affected zone behind the melt pool. These recordings can be used to identify localized areas of elevated temperature caused by the insulating effect of the subsurface defects, which impede heat transfer into the substrate. This dataset is valuable for researchers working on process monitoring, defect detection algorithms, and the validation of thermal simulations in additive manufacturing. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.15727369 ER - TY - GEN A1 - Sauer, Christian A1 - Schiffler, Andreas A1 - Höfflin, Dennis A1 - Hartmann, Jürgen T1 - Temporally Gated Active Thermography for Defect Detection in Laser-Based Powder Bed Fusion of Metals - Dataset N2 - This HDF5-dataset contains in-situ high-speed infrared thermography data acquired during the Laser-Based Powder Bed Fusion (PBF-LB/M) process. The data was collected using a Synchronized Path Infrared Thermography (SPIT) setup, which employs a dual-scanhead configuration to guide both the processing laser and the thermal camera's field of view. The primary feature of this dataset is the application of a temporally gated acquisition strategy. The infrared camera's integration time (800 µs) was synchronized with a modulated processing laser (500 Hz) to capture thermal data exclusively during the laser-off phases. This method effectively isolates the material's thermal emission from high-intensity laser reflections. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.17747278 ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Ring, E.F.J. A1 - Ammer, K. A1 - Land, D. A1 - Thomas, R. A1 - Hand, J.W. ED - Zhang, Z.M. ED - Tsai, B.K. ED - Machin, G. T1 - Infrared and Microwave Medical Thermometry in Radiometric Temperature Measurements Part II BT - Applications T2 - Experimental Methods in the Physical Sciences Y1 - 2009 UR - http://permalink.bibkatalog.de/BV010604537 SN - 978-0-12-375091-4 VL - 43 SP - 393 EP - 448 PB - Elsevier Academic Press CY - Amsterdam ER - TY - CHAP A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Struß, O. A1 - Gaertner, R. A1 - Ishii, J. ED - Zhang, Z.M. ED - Tsai, B.K. ED - Machin, Graham T1 - Industrial Applications of Radiation Thermometry, in Radiometric Temperature Measurements Part II BT - Applications T2 - Experimental Methods in the Physical Sciences, Volume 43 Y1 - 2009 UR - http://permalink.bibkatalog.de/BV010604537 SN - 978-0-12-375091-4 VL - 43 SP - 1 EP - 56 PB - Elsevier Academic Press CY - Amsterdam ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Edler, F. T1 - Simultaneous contact and non-contact measurements of the melting temperature of a Ni-C fixed-point cell JF - International Journal of Thermophysics Y1 - 2007 UR - http://permalink.bibkatalog.de/BV013298193 IS - 28 SP - 2002 EP - 2008 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Meindl, P. A1 - Taubert, Dieter Richard A1 - Werner, L. T1 - Traceable Radiometric Calibration of Semiconductor Detectors and their Application for Thermodynamic Temperature Measurement JF - MAPAN - Journal of Metrology Society of India Y1 - 2010 VL - 25 IS - 3-10 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Edler, F. T1 - Kombi-Fixpunktzelle zur Erzielung kleinster metrologischer Unsicherheiten JF - Sensor Magazin Y1 - 2007 UR - http://permalink.bibkatalog.de/BV037313622 IS - 1 SP - 20 EP - 21 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Keawprasert, T. A1 - Anhalt, Klaus A1 - Taubert, Dieter Richard T1 - Monochromator-based Absolute Calibration of Radiation Thermometers JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 1697 EP - 1706 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Anhalt, Klaus A1 - Taubert, Dieter Richard A1 - Hollandt, Jörg T1 - Absolute radiometry for the MeP-K BT - The irradiance measurement method JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 1707 EP - 1718 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Friedrich, R. A1 - Gutschwager, B. A1 - Taubert, Dieter Richard T1 - High-Accuracy Radiation Thermometry at the National Metrology Institute of Germany BT - the PTB JF - High Temperatures - High Pressures Y1 - 2005 VL - 35/36 IS - 4 SP - 379 EP - 415 ER - TY - JOUR A1 - Hartmann, Jürgen T1 - High-temperature measurement techniques for the application in photometry radiometry and thermometry JF - Physics Reports Y1 - 2009 UR - http://permalink.bibkatalog.de/BV012962270 VL - 469 SP - 205 EP - 269 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Völker, S. T1 - Thermal management of light sources JF - International Journal of Thermophysics Y1 - 2011 UR - http://permalink.bibkatalog.de/BV013298193 IS - 32 SP - 513 EP - 522 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Gutschwager, B. A1 - Struss, O. T1 - Strahlungsthermometrie BT - Temperaturen berührungslos messen JF - Automatisierungstechnische Praxis Y1 - 2006 IS - 6 SP - 70 EP - 81 ER - TY - JOUR A1 - Hartmann, Jürgen A1 - Hollandt, Jörg A1 - Anhalt, Klaus T1 - Radiation thermometry capabilities of the PTB up to 3200 K JF - MEASURE Y1 - 2008 IS - 3 SP - 26 EP - 34 ER -