12 April 2004 The NPL wide-area MIR calibration source
Author Affiliations +
The demand for improved radiometric accuracy of the remote sensing instrumentation used for diagnostic applications involving hot gas emission spectroscopy requires regular “in-field” recalibration. The most convenient calibration source for such applications is a large emitting area blackbody capable of operating at temperatures approaching 1000 K which is also compact and portable. NPL in collaboration with the University of Reading have designed and assembled a large emitting area blackbody that meets these requirements. The blackbody design is based on a grooved base that is electrically heated to temperatures up to 1000 K. The base is coated with a high emissivity coating, which does not deteriorate during prolonged heating under atmospheric conditions. This base is enclosed by a specularly reflecting cavity that is water-cooled. Monte Carlo calculations were used to design the shapes of the base and reflective cavity to ensure that despite a cavity depth of 203 mm and a black body aperture diameter of 102 mm, the spectral radiance of the blackbody is known with a 1% uncertainty in the 2.5 μm to 14 μm wavelength range. The presentation will describe the design of the blackbody and the processes used for selecting the black coating of the base and the reflective coating of the specularly reflecting cavity.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Martin Robert Dury, Evangelos Theo Theocharous, Neil J. Harrison, Moira Hilton, Nigel Fox, "The NPL wide-area MIR calibration source", Proc. SPIE 5405, Thermosense XXVI, (12 April 2004); doi: 10.1117/12.563841; https://doi.org/10.1117/12.563841

Back to Top