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Improving light and heat spectra measurements

Date:
October 30, 2013
Source:
Physikalisch-Technische Bundesanstalt (PTB)
Summary:
Whether you want to investigate objects in space, characterize the quality of light sources, optimize photovoltaics modules or analyze chemical compounds, measuring the spectrum of light- or heat sources is often the method of choice. Conventional procedures thereby generate radiation distribution curves which are distorted and have to be subsequently corrected. Scientists have now developed a mathematical procedure which yields clearly improved results and can be applied in numerous fields of radiometry and photometry. The software required can be downloaded free of charge.
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Improving light and heat spectra measurements.
Credit: Image courtesy of Physikalisch-Technische Bundesanstalt (PTB)

Whether you want to investigate objects in space, characterize the quality of light sources, optimize photovoltaics modules or analyze chemical compounds, measuring the spectrum of light- or heat sources is often the method of choice. Conventional procedures thereby generate radiation distribution curves which are distorted and have to be subsequently corrected. The Physikalisch-Technische Bundesanstalt (PTB) has now developed a mathematical procedure which yields clearly improved results and can be applied in numerous fields of radiometry and photometry.

Measuring systems for optical or thermal radiation such as, e.g., radiometers, spectrometers and photometers, generate spectral distribution curves which shed light on the characteristics of the measured radiation (e.g. its luminance, its colour quality, its temperature or its wavelength). These distribution curves, however, exhibit distortions which are caused by the measuring instrument used. There are correction procedures, but these are reliable to a certain extent only.

Scientists at PTB have found a new approach to this problem: they have, for the first time, considered the occurring distortions as mathematical convolution and used the Richardson-Lucy method -- an iterative procedure -- for the deconvolution. An issue which has often been discussed with regard to the Richardson-Lucy method is the need for a criterion for the breaking of the iterations. In this context, a novel approach has been developed at PTB which works, in principle, automatically and independent of additional parameters. This new approach has turned out to be very robust, both in comprehensive simulations and in investigations of measurement data. The scientists hereby investigated numerous scenarios with diverse line spread functions and signal-to-noise ratios. The procedure developed in this way is suitable both to improve broadband spectral distribution curves (as occurring, e.g., in heat radiators) and narrowband distribution curves (as occurring in LEDs).

To make the method developed at PTB easily applicable, adapted software with a graphical user interface is now available. Interested companies and manufacturers of measuring instruments can download it free of charge from PTB's website: http://www.ptb.de/cms/en/fachabteilungen/abt8/fb-84/ag-842/dynamischemessungen-842.html.


Story Source:

The above post is reprinted from materials provided by Physikalisch-Technische Bundesanstalt (PTB). Note: Materials may be edited for content and length.


Journal Reference:

  1. S Eichstädt, F Schmähling, G Wübbeler, K Anhalt, L Bünger, U Krüger, C Elster. Comparison of the Richardson–Lucy method and a classical approach for spectrometer bandpass correction. Metrologia, 2013; 50 (2): 107 DOI: 10.1088/0026-1394/50/2/107

Cite This Page:

Physikalisch-Technische Bundesanstalt (PTB). "Improving light and heat spectra measurements." ScienceDaily. ScienceDaily, 30 October 2013. <www.sciencedaily.com/releases/2013/10/131030092954.htm>.
Physikalisch-Technische Bundesanstalt (PTB). (2013, October 30). Improving light and heat spectra measurements. ScienceDaily. Retrieved August 30, 2015 from www.sciencedaily.com/releases/2013/10/131030092954.htm
Physikalisch-Technische Bundesanstalt (PTB). "Improving light and heat spectra measurements." ScienceDaily. www.sciencedaily.com/releases/2013/10/131030092954.htm (accessed August 30, 2015).

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