A5084639418- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Advanced Sensor Technologies Research
- Radiative Heat Transfer Studies
- Scientific Measurement and Uncertainty Evaluation
- Chemical Thermodynamics and Molecular Structure
- Spectroscopy and Laser Applications
- Nuclear Physics and Applications
- Digital Economy and Work Transformation
- Thin-Film Transistor Technologies
- Laser-induced spectroscopy and plasma
- Particle Detector Development and Performance
- Iron and Steelmaking Processes
- Retirement, Disability, and Employment
- Transition Metal Oxide Nanomaterials
- Urban Heat Island Mitigation
- Diamond and Carbon-based Materials Research
- Color Science and Applications
- Employment and Welfare Studies
Manufacturing Technology Centre (United Kingdom)
2019
Coventry (United Kingdom)
2019
National Physical Laboratory
2006-2017
University of Reading
2004
The thermodynamic temperature of the point inflection melting transition Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 0.18 K 1597.39 0.13 respectively, freezing Cu 1357.80 0.08 where symbol represents 95% coverage. These results are best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. good agreement between institutes suggests that...
The eutectic alloys rhenium–carbon, platinum–carbon and cobalt–carbon have been proposed as reference standards for thermometry, with temperature uncertainty values specified within the mise en pratique of definition kelvin. These investigated in a collaboration eleven national measurement institutes laboratories. Published results reported point-of-inflection melting curve extremely low uncertainties. However, to be considered it is necessary stipulate what phenomenon value has ascribed to;...
Sintered polytetrafluoroethylene (PTFE) is highly reflective and widely used as a reference standard in remote sensing, radiometry, spectroscopy. The relative change output flux from PTFE integrating sphere over the room temperature phase transition at 19°C has been measured monochromatic wavelength of 633 nm 1.82±0.21%. was attributed to small 0.09±0.02% total hemispherical reflectance PTFE, caused by its material density result transition. For majority users, this unlikely impact...
This paper describes a thorough investigation of the NPL Vega BB3500 furnace to improve quality and duration melt plateaux Re–C eutectic cell. The results this have shown that position cell within is most critical factor for optimizing fixed-point performance. It was found better performance could be obtained from with uniform ring resistance than highly non-uniform profiles, but effect relatively small. When high (hot) rings were deliberately introduced on either side cell, at distance...
The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison NPL's Absolute Radiation Thermometer (ART), "THermodynamic Optical Radiometer" (THOR) is more portable and compact, much lower size-of-source effect improved performance in other parameters such as sensitivity. It been designed for calibration whole instrument via radiance method, removing...
Abstract We have assessed the absolute spectral responsivities of three-element trap detectors calibrated against National Physical Laboratory primary standard cryogenic radiometer at eight krypton ion laser emission wavelengths over an approximate period 20 years. As expected, we observed that decrease with time. Additionally, found as wavelength decreases, ageing rate increases. At 356.4 nm, average responsivity around −1800 ppm yr −1 is reported. While longer wavelengths, slowest ageing,...
More than twenty years of the absolute responsivity measurements from a set three-element trap detectors that have been calibrated against NPL primary standard cryogenic radiometer are assessed. For Krypton ion laser emission wavelength 356.4 nm, total decrease in around 3 % was recorded over measurement history. The year-on-year changes relatively linear, allowing for easy prediction future performance particular detector. Potential causes detector discussed.
The demand for improved radiometric accuracy of the remote sensing instrumentation used diagnostic applications involving hot gas emission spectroscopy requires regular "in-field" recalibration. most convenient calibration source such is a large emitting area blackbody capable operating at temperatures approaching 1000 K which also compact and portable. NPL in collaboration with University Reading have designed assembled that meets these requirements. design based on grooved base...