Thermal Imaging Metrology with a Smartphone Sensor

Thermal imaging cameras are expensive, particularly those designed for measuring high temperature objects with low measurement uncertainty. A wide range of research and industrial applications would benefit from lower cost temperature imaging sensors with improved metrology. To address this problem, we present the first ever quantification methodology for the temperature measurement performance of an ultra-low cost thermal imaging system based on a smartphone sensor. The camera was formed from a back illuminated silicon Complementary Metal Oxide Semiconductor (CMOS) sensor, developed for the smartphone camera market. It was packaged for use with a Raspberry Pi computer. We designed and fitted a custom-made triplet lens assembly. The system performance was characterised with a range of state-of-the-art techniques and metrics: establishing a temperature resolution of below 10 °C in the range 600–1000 °C. Furthermore, the scene dependent aspects of combined uncertainty were considered. The minimum angular subtense for which an accurate thermal measurement could be made was determined to be 1.35°, which corresponds to a 23 mm bar at a distance of 1 m, or 45:1 field-of-view in radiation thermometer nomenclature

Variation of texture anisotropy and hardness with build parameters and wall height in directed-energy-deposited 316L steel

Directed energy deposition (DED) is an emerging technology with repair applications in critical aerospace components. Mechanical properties of DED components have been shown to vary significantly through a part, making it difficult to achieve the level of process control required for these applications. Using thermal data captured in-situ, cooling rates and melt pool dimensions were calculated and related to the final grain structure, captured by EBSD. The changes in cooling rate explain the microstructural variation between different processing parameters and through the build height. A new approach, using a cumulative anisotropy factor was implemented and correlates the variation in hardness with grain structure. Two regimes were found depending on the linear heat input in 316L, with high linear heat input resulting in great amounts of mechanical anisotropy on the component level. The relationships between thermal signature and mechanical properties suggest close control of anisotropy could be achieved by monitoring and controlling the melt pool size using a coaxial camera

Low-cost hyperspectral imaging with a smartphone

Recent advances in smartphone technologies have opened the door to the development of accessible, highly portable sensing tools capable of accurate and reliable data collection in a range of environmental settings. In this article, we introduce a low-cost smartphone-based hyperspectral imaging system that can convert a standard smartphone camera into a visible wavelength hyperspectral sensor for ca. £100. To the best of our knowledge, this represents the first smartphone capable of hyperspectral data collection without the need for extensive post processing. The Hyperspectral Smartphone’s abilities are tested in a variety of environmental applications and its capabilities directly compared to the laboratory-based analogue from our previous research, as well as the wider existing literature. The Hyperspectral Smartphone is capable of accurate, laboratory- and field-based hyperspectral data collection, demonstrating the significant promise of both this device and smartphone-based hyperspectral imaging as a whole

Gevolgen van COVID-19 voor de rechtspraak en kwetsbare rechtzoekenden: een onderzoek naar maatregelen en de positie van rechtzoekenden binnen het straf-, civiele jeugdbeschermings-, en vreemdelingenrecht

NWO10430032010019Criminal Justice: Legitimacy, accountability, and effectivit

The 2009 edition of the GEISA spectroscopic database

The updated 2009 edition of the spectroscopic database GEISA (Gestionet Etudedes Informations Spectroscopiques Atmospheriques ; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1. GEISA, continuously developed and maintained at LMD (Laboratoirede Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS(France) ‘‘Ether’’ Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated managements of software facilities. More than 350 researchers are registered for online use of GEISA