Numerical simulations developed to understand high temperature industrial processes, such as welding, need to be fed with thermophysical properties of the matter over temperature and with input parameters such as the absorbed part of the laser power, which is usually used as heating source. Literature mentions values of emissivity, which can be approached as the absorptivity through...
Dynamic thermal infrared imaging remains a challenging task for uncooled microbolometer-based cameras, primarily due to their limited thermal time constants and the resulting motion-induced blur. In order to investigate these effects, we present a compact dynamic laboratory test bench designed to emulate the passage of hot objects from the camera perspective without physically moving heated...
Ultra-thin recycled polyethylene terephthalate (rPET) polymer films, with thicknesses ranging from 20 to 200 µm, are widely used in applications such as coatings, packaging, surface functionalization, and labelling. Several industrial deposition processes operate at non-ambient temperatures, typically between 20 and 120 °C, making accurate temperature monitoring of these films essential....
Introduction
Highly concentrated solar radiation can be used in solar-thermochemical water splitting to produce hydrogen as an energy carrier. This production pathway shows a high efficiency potential as an alternative to PV coupled to electrolysis. In solar tower plants, receiver-reactors (like the R2Mx reactor [1]) convert high temperature heat to chemical energy in a...
The Data Reference Method (DRM) is a method developed at PTB for determining and correcting the non-uniformity of the responsivity of the individual detector elements of two-dimensional resolution cameras. The method is based on an intended horizontal and vertical displacement of the camera in front of a radiation source and the successive recording of several (at least three) offset images of...
The size-of-source effect (SSE) is among the largest contributors to measurement uncertainty in thermography. It describes a systematic deviation of the measured temperature of an object with respect to its size and results from a variety of effects, such as diffraction, detector discretization, aberrations, and scattering. According to theory, the SSE can be explained by the modulation...
The continuous improvement of aero-engines, driven by industrial and environmental motivations, implies an ever-increasing level of thermal and mechanical stresses within the turbines. structural materials (titanium, nickels-based superalloys, TBCs, etc.) are stressed to their performance limits and altered by environmental degradation mechanisms involving changes in surface and subsurface...
Early detection of fatigue damage in metallic structures and complex components is limited by slow and often destructive procedures based on S–N curves, crack monitoring, and post-failure crack analysis. Infrared thermography (IRT) has recently been employed to identify ``invisible'' fatigue damage in thermosetting epoxy resins through a thermodynamic indicator based on entropy generation. ...
Temperature represents a key characteristic in additive manufacturing (AM) processes for metals. As a physical quantity, temperature provides a direct measure of the actual process state and can be an indicator for the process quality. Consequently, process evaluation based on temperature measurements, rather than solely on the monitoring of process radiation in gray values, is expected to...
Thermal Protection Systems (TPSs) of space vehicles must withstand extreme thermal fluxes and high temperatures during atmospheric re-entry, making emissivity one of the key parameters to be accurately characterised. Infrared thermography, combined with complementary diagnostics such as pyrometers and thermocouples, enables emissivity characterisation of TPS materials when heated under...
Within the framework of Brighter project new multispectral (MS) microbolometers are designed, developed and integrated in new infrared camera prototypes. These prototypes are implemented and tested on various use-cases. In the present study, the Sense-City (https://sense-city.ifsttar.fr/) large scale facility was selected to conduct experiments on urban small cities buildings and roads in...
Unmanned aerial vehicles (UAVs) equipped with infrared imaging systems have emerged as a promising tool for the assessment of energy performance in building envelopes. By enabling non‑contact, rapid, and wide‑area observations, UAV‑based thermal inspections offer new possibilities for identifying heat loss and performance irregularities that are difficult to detect using conventional,...
Digital Metrology is undergoing a transformation as analogue, paper-based calibration certificates are replaced by machine-readable and machine-interoperable formats, like the Digital Calibration Certificate (DCC). This is especially advantageous in use-cases like the temperature calibration of thermography cameras, that need to deal with multi-dimensional measurement data recorded under a...
Since about 10 years, Safran develops the use of active thermography for Non Destructive Inspection of aircraft and aerospace components. Initial applications were dedicated to composites parts, monolithic or sandwich, such as components for aircraft nacelles. The efficiency of the method lead Safran to investigate also the extension for application on metallic components.
Considering...
Thermochromic liquid crystals (TLC) provide high spatial resolution surface thermography by mapping temperature to color. Quantitative use, however, requires robust calibration with the support of IR thermography, and careful control of optical artifacts. However, direct IR-referenced calibration in the final configuration is often impracticable in water-flow experiments where the surface is...
Various IR camera suppliers sell their products, regardless of their intended field of use and according to specifications that primarily address temperature measurement applications. For NDT applications by Infrared Thermography, users often select their cameras based on rather arbitrary criteria (wavelength range, acquisition frequency, temperature range, field of view) without taking into...
