MultiFixRadSoft

MultiFixRadSoft is an open-source desktop GUI application for relative primary radiation thermometry (RPRT), developed at TÜBİTAK UME in accordance with the Mise-en-Pratique for the kelvin (MeP-K). It covers the complete measurement workflow in a single tool — from raw time–temperature–signal data through melting-plateau analysis, instrument corrections, Sakuma–Hattori scale fitting, and full GUM-compliant uncertainty propagation.

The software supports ITS-90 metal fixed points and metal–carbon / metal-carbide–carbon eutectic high-temperature fixed points (HTFPs) , with flexible calibration schemes from a single fixed point up to N points. The software has been validated through comparison with manual analyses and published reference datasets. It is specifically designed to facilitate the adoption of primary thermodynamic temperature realization methods within the redefined SI framework by reducing the mathematical and computational burden on emerging National Metrology Institutes (NMIs), Designated Institutes (DIs), and industrial laboratories.