OREANDA-NEWS. Shvabe Holding scientists developed a fundamentally new FTIF modulation method for measuring refraction indicator of dark and light-dispersing media.

FTIF - frustrated total internal reflection - is a phenomenon based on the penetration of a light wave from optically denser medium into a less dense medium subject to certain conditions. The method created by the specialists of Shvabe Holding enterprise Shvabe - Tech Lab JSC is designed for refractometers - devices measuring light refraction indicator in transparent media, as well as in dark and light-dispersing media, for example, oil.

"The essence of the method consists in the direction of light from the side of a measuring prism, then the smooth change of light incidence angle is accompanied with a slight high frequency modulation of the incidence angle (temporal variation for a number of specified characteristics). Variable signals received from a photodetector are detected and analyzed according to their amplitudes, which allows to define a pseudo-critical light incidence angle and the sought refraction indicator even in case of a high value of studied medium absorption coefficient, when common refractometers can not operate," reported Shvabe Deputy CEO of R&D and innovative development Nikolay Rakovich.

The developed method significantly differs from previously used methods. The difference consists in the fact that it allows to measure a material part of a complex refraction indicator even in cases of significant values of an imaginary component. Thus it provides an opportunity to a wider use of refractometer methods of analysis of dark and light-dispersing substances.

Due to a number of advantages of this innovation it will be in demand for conducting scientific and production research studies, which require to use refractometer methods of analysis in those cases, where these methods could not be applied previously, for example, to study oil, its extracts, dyes in chemical industry, paste-like products in food industry, biological samples in medicine and veterinary.