Development of Measures for Metrological Support of Raman Spectroscopy

Raman spectroscopy is widely used in various industries and requires the use of special means for metrological support. In this study, prototype measures made from inorganic glasses activated with metal ions to excite fluorescence lines at specific wavelengths were developed for calibrating Raman spectrometers and microscopes on a scale of relative intensities with metrological traceability to SI base units. The study established the metrological characteristics of prototype measures, where the certified characteristic is the relative intensity of the reproduced fluorescence radiation. The maximum expanded uncertainty of measuring the relative fluorescence intensity at a coverage factor k = 2 is 9.4%, 5.2%, and 2.8% for prototype measures designed to reproduce the relative fluorescence intensity when excited at wavelengths of 532 nm, 633 nm, and 785 nm, respectively. By certifying the measures on the laser Raman confocal microscope Confotec NR 500, part of the GET 196-2015, metrological traceability can be established through the scale of relative intensities of the GET 86-2017 microscope, providing traceability to SI units of the “(light) energy flux” value. These findings have practical significance, since they allow the calibration characteristics of Raman microscopes and spectrometers to be established and monitored on a scale of relative intensities.